The Stepping Maze. Dan Kotler, #6

History has its secrets. Someone wants them all. Book Six of the Dan Kotler archaeological thrillers History's most dangerous secrets are locked behind six feet of steel beneath the streets of Manhattan. Deep underground lies the Black Chamber-the legendary codebreaking room that helped birth the NSA. Someone is willing to kill to get inside. When two physics professors are abducted by a ruthless professional killer and left with dwindling air and food, the clock starts ticking.
FBI Agent Roland Denzel and Dr. Liz Ludlum are drawn into a deadly game by a mysterious manuscript packed with centuries-old riddles. Is this the key to unlocking the Black Chamber? What other forbidden truths does it conceal?Dr. Dan Kotler returns in a pulse-pounding codebreaking thriller. To save the hostages and stop a catastrophe, he must navigate the Stepping Maze - a labyrinth of enigmas where one wrong step could doom them all.
Some doors were never meant to be opened. "J. Kevin Tumlinson's thrillers are a throat-clutching ride. If you love historical mysteries crafted with action and adventure, don't miss [Tumlinson's books]!"- James Rollins, #1 New York Times Bestseller of Arkangel"With the pacing of a blockbuster and the depth of literary fiction, Kevin Tumlinson crafts stories that are both intellectually engaging and impossible to put down-prepare to lose sleep."- J.
D. Barker, New York Times Bestselling Author"Where [Tumlinson's work] excels most is its cross-genre appeal. All of these disparate elements shouldn't work together, but they do, and a big reason is that this novel is just so damn fun."- Jeff Daugherty, BookTrib