FeaturedThriller & Suspense

The Stepping Maze


Loved it! 😍

"The Stepping Maze" is a fantastic whirlwind ride that will keep you guessing until the very end.


History has its secrets, and someone wants them all.

Behind six feet of steel, buried under the streets of Manhattan, lies the Black Chamber—a room that once housed a team of codebreakers who would one day help to found the NSA.

“Imagine a writer that combines the best aspects of Cussler, Rollins, Berry, and Brown all into one. That’s Kevin Tumlinson.”
—Ernest Dempsey, Author of The Forbidden Temple

Abducted by a brutish professional killer, two physics professors are left with little food and limited air. Time is running out.

Agent Roland Denzel and Dr. Liz Ludlum are led to a government-sealed room by an unseen figure, where they find a century-old manuscript filled with riddles. Is it the key to opening the Black Chamber? What other secrets does it hold?

Dan Kotler returns in this codebreaking thriller, filled with enigmas, mysteries, and danger at every turn. Kotler must solve the Stepping Maze before time runs out ... for everyone.

The Stepping Maze is the sixth full-length novel in the Dan Kotler Archaeological thrillers.

In his latest book featuring the character Dan Kotler, Kevin Tumlinson navigates his genre with a level of skill that makes The Stepping Maze a truly enjoyable read. The plot is fast paced, full of surprises, yet still easy to follow and keep track of the details. His characters are well-developed but, have not fallen into stagnation. They continue to evolve, learning about themselves as we learn about them. Even technical considerations enhance the novel.

As to be expected in any good thriller, Tumlinson opens immediately into the action, and keeps a quick paced plot from there. He divides the book into parts, allowing each story arc its own section within the larger narrative. This technical detail pleasantly accentuates the pace of the novel. Just when everything seems set to wrap up, an entirely new set of questions arise, beginning the next arc sequence. Plot twists and turns make The Stepping Maze a real page-turner, and the structure gives readers a sense of closure at the end of one act before the next begins.

Coming into this novel with no previous exposure to Tumlinson’s writing, it was immediately evident the characters had been developed over a significant time-span. It took a couple of chapters to be certain, but once I had confirmed this was not the first book in the story line, I found myself able to enjoy the book as a stand-alone piece. Occasional references to previous exploits are well crafted. Tumlinson manages to pique the reader’s interest alluding to a previous episode without distracting from the story at hand, nor confusing the reader with the unfamiliar reference. Enough background is given for the reader to get a sense of growth characters have undergone through previous adventures without having read the other works.

My only complaint of this first edition has to do with editing. I found less than half a dozen typographical errors in the text, but each of them created enough dissonance as to force a pause to identify and mentally correct the error and flow of the story. This example of uncoordinated tense comes from chapter 9:

“The man—large, muscular, and still wearing the balaclava—casually reach into the box and picked her up, almost one-handed.“

It is small, but in the quickstep pace of this novel, bumping into one of these small errors can feel a bit like hitting a pothole while speeding down the freeway.

Editing misses aside, fans of thrillers will enjoy Tumlinson’s latest work. Perhaps not as intricate as a Dan Brown piece, but in my opinion, at least as well written. I highly recommend this novel and will be seeking more works by this author for my collection.

Reviewed by

I love thrillers and suspense, and Reedsy has kept me inspired. In 2020, though my focus will be on creating my own original stories, I will continue to write reviews through the same lens as I hope others will consider my own writing in the future. Happy Reading!


History has its secrets, and someone wants them all.

Behind six feet of steel, buried under the streets of Manhattan, lies the Black Chamber—a room that once housed a team of codebreakers who would one day help to found the NSA.

“Imagine a writer that combines the best aspects of Cussler, Rollins, Berry, and Brown all into one. That’s Kevin Tumlinson.”
—Ernest Dempsey, Author of The Forbidden Temple

Abducted by a brutish professional killer, two physics professors are left with little food and limited air. Time is running out.

Agent Roland Denzel and Dr. Liz Ludlum are led to a government-sealed room by an unseen figure, where they find a century-old manuscript filled with riddles. Is it the key to opening the Black Chamber? What other secrets does it hold?

Dan Kotler returns in this codebreaking thriller, filled with enigmas, mysteries, and danger at every turn. Kotler must solve the Stepping Maze before time runs out ... for everyone.

The Stepping Maze is the sixth full-length novel in the Dan Kotler Archaeological thrillers.



Dr. Leopold Marvin fell face-first to the smooth, cement floor, sliding a bit from the momentum of being shoved into the room. 

He couldn't see. The weave of the hood over his head let in only a tiny fraction of light. He could hear sounds, mostly the shuffling of feet and then a metallic click. It sounded ominous, but he couldn't imagine what it might be. He waited. 

Gloved hands took hold of his forearms, which were pinned behind his back and bound with rough twine. 

There were two men, large, strong. Stronger than he was, at least, though that wasn't admitting much. One of the men held him while the other slipped a bladed between his wrists and cut the twine.

They dropped him to the floor again, knocking the wind out of him. In a few moments, there was the sound of a very large and heavy door being swung closed. The thud of it was loud and solid and imposing, giving Dr. Marvin a clear mental image of it despite the hood. He pictured the massive thickness of a stone being rolled in front of a tomb.

A series of loud clacks followed, and then silence.

Dr. Marvin lay on his stomach, not sure if he should move. Eventually, he raised his hands to the hood, tugging the drawstring loose and pulling the material away from his eyes. He worked the gag out of his mouth and took a deep breath. 

He was in a room. It looked like an office—but everything seemed a few generations removed from present day. Something out of the fifties, maybe? There were desks, tables, chairs, old lamps with lead-glass shades. There were bookcases filled with unmarked spines. There was an ancient-looking refrigerator and sink at one end of the room, and a hot plate on the counter. 

It was like being kidnapped and thrown into the past. What was this place, a bomb shelter?

"Leo?" a familiar male voice echoed dimly from one darkened corner of the room.

Dr. Marvin rose to his feet, reaching for the edge of a desk to steady himself. He felt his heart pounding, and he wanted to throw up. He was scuffed and bruised, and a bit cold. They had grabbed him from his bedroom, his wife screaming and attacking them until they knocked her unconscious. God he hoped she was just unconscious.

He looked into the darkness, at the figure across the room, recognizing him instantly as he stepped into the light. 


Dr. Robert Wiley was likewise dressed in his pajamas, and he padded forward in bare feet. "Leo, they got you too?"

"Who are they?" Leo asked, shaking.

Bob shook his head. "I have no idea. I woke up with one of them standing over me. He shoved a rag in my mouth, and then the two of them tied me up and brought me here."

Leo nodded. "Same with me. Did they say anything? Do ... do you know what they want?"

Bob shook his head. "No idea. I've been here for hours, and until they brought you in a guy was standing in the doorway, blocking me from getting out. He didn't say a word. Wouldn't answer any questions. I started calling him Gill, trying to ... I don't know, humanize him? Get a rise out of him?"

"Did it work?" Leo asked, pulling an old wooden, rolling office chair over and taking a seat. He was rubbing his bruised knees.

"He wouldn't react. I eventually just found a spot in the back and hid out. I don't know what I thought would happen, but then you were here."

Leo nodded. He was trying not to think of his wife. Thank God his daughter and his son were out of the house these days. They should be safe. He hoped.

He looked up. "What about you, Bob? What about your family?"

"Vacation," Bob said. "Lillie and Jeannie went to the lake house two days ago. I was supposed to join them in the morning. I had to wrap up some grading, and I met with some students to discuss their dissertations. I could have just skipped it," he said, looking away. Quietly he said, "Now I wish I'd gone."

Leo nodded, but he was already thinking about their predicament. He rose from the office chair and went to the large, steel door, putting his hands on it. The metal was cold, and it reminded him that there was a slight chill in the room. He held his arms to his chest. 

"Yeah," Bob said. "Kind of cold. I found a couple of cots and blankets in the back. Not much, but it'll help."

"Any way out?"

Bob rolled his eyes. "Sure, Leo. I left hours ago."

"I mean, any potential way out?"

Bob shook his head. "None I've found. I haven't found any other doors or windows. But we can look together. I have a feeling we're going to be here for awhile."

Leo nodded. He looked around and frowned. "What the hell is this place?"

"It seems to be some kind of old office," Bob replied. "Government stuff, I think. Most of the books I've found are manuals. There's some stuff about cryptography. References."

"Cryptography?" Leo asked. "Codebreaking?"

Bob nodded.

What the hell was going on here? Why were he and Bob trapped here? What was this place?

He turned again to the door and started pounding on it, yelling for help. His hands became sore after a moment, and he stopped.

"That door is thick," Bob said from behind him. "About six feet, I think. Steel."

"Six foot of steel? What is this, a bank vault?"

"Could be," Bob said. "No windows. Steel walls. No other exits. It could definitely be a bank vault."

"But why would anyone kidnap us and put us in a bank vault?" Leo asked, his voice going up an octave as the panic started to rise again.

Bob shook his head. "I don't know, Leo. But this is where we are." He said this last calmly, looking Leo in the eye. It was the way Bob had delivered bad news to students, about grades or about the reality of the state of their dissertations. Leo had sat alongside him and several other professors at enough dissertation reviews to know the look and what it meant. Be calm. Accept reality. Be ready to work past this.

He was right. Leo had to calm down. Relax. Center himself. His blood pressure was on the rise, he could tell. 

He sat back down, and Bob disappeared only to return after a moment with the blankets. Leo thanked him, absently, and allowed Bob to drape a blanket over his shoulders as he stared wide-eyed down at the floor.

"It's going to be ok," Bob said, pulling up an office chair next to his colleague. 

The two of them had taught in the same department for the past thirty years, imparting the intricacies of physics and quantum mechanics to graduate students who were, as far as Leo could tell, getting dumber with each new incoming class. They were more concerned about safe spaces and cry closets and using jazz hands instead of giving applause than they'd ever been about the intricacies of quantum mechanics. No one cared about the science anymore. 

Leo had been thinking of retiring. Bob, he knew, was supposed to leave at the end of the following semester. 

Two fewer conservative old white men in positions of authority on an increasingly liberal campus. They'd probably be cheered out of the building. No one would be more thrilled to leave all the insanity behind than Leo.

He and Bob weren't friends. Not really. Bob was a nice enough guy, but he drove Leo nuts half the time. The two of them disagreed on nearly everything that wasn't explicitly outlined in a textbook and sometimes went on a row over the textbooks themselves. They argued, but Leo found that he was ultimately the only one who got truly angry and irritated, while Bob seemed to smile through it all, taking everything in small steps, coming through their disagreements as if he was oblivious to their disagreeing at all. It was infuriating. Leo wanted to tie him to a chair and strap explosives to him, half the time.

But the point was that they were not friends, and really had to do with each other, outside of their work at the university.

They spent no time together. They shared no projects or papers. As far as Leo could recall, neither of them had ever visited the other at home, unless there was some sort of obligatory social event. Even then, conversations were kept to socially benign topics. There was no bonding.

So their jobs—that had to be the reason they were grabbed. 

What did these people want with a couple of old, retiring physics professors? 

Why bring them here, to some weirdly anachronistic government office, crammed full of code-breaking manuals? 

What was it these people hoped to gain? And would they come back to let the two of them out, or leave them to die here?

The questions were piling up, and Leo wasn't getting any closer to the answers. 

He turned to Bob. "What if we die here?"

Bob considered the question, nodded, and said, "That would be terrible. But heck, it'd almost be like therapy, wouldn't it? Nothing puts the petty problems of life into perspective like the prospect of dying."

Leo stared at the man for a moment, wanting to shout at him for his optimism as they huddled under blankets in this terrifying space. 

He huffed and slumped in the chair. 

Bob was right. It would be terrible. And there was really nothing they could do about any of it. All they could do was wait.


Dust drifted in motes through shafts of artificial light, joining its brethren on the piles of books and antique objects. The room was packed with the accoutrement of science, though a couple of generations removed from modern day. 

Agent Roland Denzel had seen rooms like this before. A lot more of them, in fact, since taking on Dr. Dan Kotler as his partner. 

Kotler wasn’t here, though. And it was left to Denzel and Dr. Liz Ludlum to go over the scene, to try to find some hint of what was going on.

“Shouldn’t we call Dr. Kotler?” Ludlum asked. She nodded to the piles of papers, the antiquated scientific instruments, and the artifacts that were clearly from another era. “This is kind of his thing.”

Denzel shook his head. “He’s at a dig site … somewhere. I don’t have all the details. He’s taking a sabbatical.”

Ludlum squinted. “ A sabbatical? But he’s still at a dig site?”

“A sabbatical from Historic Crimes,” Denzel said.

Ludlum picked up the stress and irritation in his voice and didn't push.

They turned back to the scene in front of them. 

“Two people, trapped in …” Denzel hesitated and looked at Ludlum. “What would you say that thing is?”

“A vault, maybe?” Ludlum shrugged.

“We can’t afford to wait for Kotler to get here anyway,” Denzel said. “Who knows how much time they have?”

Two other agents entered the room, each carrying a forensics kit, taking samples and photographs, noting anything they found. Liz Ludlum's new team. Now that she was officially the Lead Forensic Specialist for Historic Crimes, she'd been given some leeway and a bit more authority than she'd enjoyed with the NYPD.

Ludlum carried an antique doctor’s bag—something left to her by her grandfather. It had her own kit inside, and she opened the bag to fish out a notebook.

“We’re at the right address, and this is pretty much what the letter described. ‘To open the door, run the Stepping Maze. Your tools await in the room where it all started.’ A riddle, I think.”

“Mean anything to you?” Denzel asked.

Ludlum shook her head. “Not really. This really isn’t my area. This is more …”

“Dr. Kotler’s thing, I know,” Denzel grumbled.

Ludlum was quiet for a moment. She folded the notebook closed and slipped it into her pocket, snapped the doctor’s bag shut and left it at her feet.

“Careful with that,” Denzel groused. “Someone might think it’s evidence, in the place.”

“No chance,” Ludlum said, shaking her head. “First thing I taught my team was to never touch my bag.” She looked at Denzel, sighed, and asked, “What happened, in Antarctica?”

Denzel shrugged. “Nothing that doesn’t happen all the time. We stopped the bad guy. Bad girl. Sorry,” he said, giving Ludlum a sheepish grin as if he’d committed a faux pas against her entire gender. “Got cold, got shot, rested up and came home.”

“Gail McCarthy,” Ludlum nodded. “Seems like Dan hasn’t gotten over it.”

"Kotler will be fine," Denzel said, an edge coming back to his voice. "Let's focus on figuring this out, so two more people don't end up dead."

Ludlum couldn’t argue with that. But she was having trouble figuring what this room and its contents, as interesting and unusual as they were, had to do with two prominent physicists being kidnapped and locked in an impenetrable cell buried under New York City. She did know that the note that had led them here had been addressed to Denzel specifically. 

It had not mentioned Kotler. Which was, in itself, pretty strange. Because this had Kotler written all over it. 

One of Ludlum’s team called to them from across the room, and she and Denzel made their way through the antiques and artifacts and equipment. Maybe this place is the Stepping Maze, Ludlum thought, high-stepping over a stack of slide projector carousels that looked as if they dated to the 50s. 

This place was going to take a year to catalog.

"Dr. Ludlum, we've found a reference to ‘stepping maze.' It's written on this." In a blue-gloved hand, he held up a small ream of aged typewriter paper bound with three brass brads. 

Ludlum pulled on gloves of her own and took the manuscript, holding it up to inspect under the work lights the team had brought in. Denzel crowded her a little, looking over her shoulder.

On the cover of the manuscript, in neat type, were the words "Cryptographic Applications of Heisenberg's Theory." In one corner of the page, in a scrawl of handwritten characters, was a note: "Could apply to 'stepping maze.'"

They had their thread. This had to be what the mysterious letter writer had intended them to find. It was a thick tome and flipping through the first few pages, Ludlum could tell it was going to be out of her league. She recognized some of the science, but it quickly got a level at which she was only an amateur. Notations from high-level quantum physics and mathematics adorned nearly every page. They'd need to bring in some experts to run through this.

“Has to be it,” she said, glancing at Denzel.

The agent looked startled and took the manuscript form her in his own gloved hands. "You see this?" he asked, holding it up and turning it to keep the cover in the light.

Her hands had obscured the small print at the bottom of the cover as she’d held it, and she had overlooked something in her casual inspection. But now it stood out like a neon sign.

Dr. Daniel F. Kotler

The author’s name in crisp, typed letters.

“That’s …” Ludlum started. 

“How old would you say this is?” Denzel asked her.

She shook her head. “I could get a sample and have it dated. The paper looks aged, though. Yellowed. And it’s definitely a typewriter, not a printer. Look at the indentions. I’d say it’s at least thirty years old, maybe more. ”

“This room has been sealed for seventy years,” Denzel said. “I had to get special permission just to open it.”

“Roland, anyone could have gotten in here at any time and left that,” she said. “The person who wrote the letter …”

“I know that,” he waved. “They knew it was here, so the likely explanation is that they put it here. Or they’ve at least been in this room. Have we seen any evidence that anyone was in this room before we got here? Aside from whoever left it this way?”

She shook her head. "Not that I'm aware. The locks and the seals were all intact. There are no windows. There's ventilation, but it was added when the doors were sealed. The vents are maybe six inches wide, if that." She looked around the room, taking in the piles of boxes, desktops covered in scientific equipment, shelves crammed with reference books. "We're just getting started here. Maybe there's some other way in?"

Denzel called for one of the field agents to bag and catalog the manuscript. “When this is done, I want that at the top of the pile. Whatever else you find, I want that examined first. And I want it scanned and sent to my phone.”

He turned, pulling off his gloves as he moved to the door. 

Ludlum followed, just on his heels. “O-ok … But Roland … Agent Denzel!” She hadn’t meant to shout, but it was the only thing that made Denzel stop short and turn to face her. “Where are you going?”

“To get Kotler,” Denzel said. “This literally has his name written all over it.”

About the author

Kevin Tumlinson is an award-winning and bestselling thriller author, with books available in hundreds of countries worldwide. Kevin is a seasoned world traveler with a long-standing career in film, television, radio, and podcasting. view profile

Published on January 25, 2019

Published by

70000 words

Genre: Thriller & Suspense

Reviewed by

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