Strange things have always happened in the Superstition Mountains of Arizona… Bizarre lights, reports of cave entrances that appear and then vanish, hundreds of mysterious disappearances…and rumors of monstrous creatures that inhabit a labyrinthine underworld. When a terrifying accident on an Arizona highway leads to a military exclusion zone and a cover-up of staggering proportions, Jack Sigler—Callsign: King, field leader of the elite and ultra-secret covert Chess Team—joined by his closest friend, archaeologist George Pierce, sets out into the desert, intent on discovering the truth. Assisted by a beautiful paranormal investigator, dogged by soldiers intent on preserving the quarantine, and pursued by a relentless legendary hitman, King soon finds himself in a race against time to prevent all out war with the creatures that inhabit the underworld. THE CALLSIGN BOOKS: Callsign: King - Underworld (42,000 words) part of a series of Chess Team novellas being released in 2011. Each of the books follows a single member of the team and are titled for them; Callsign: Queen, Callsign: Knight, etc, and are co-authored by Jeremy Robinson and five other fantastic authors. The stories take place after the events of THRESHOLD, the third Jack Sigler thriller, but are designed to introduce readers to the series. If you haven't read the novels, no worries. Enjoy the ride! PRAISE FOR ROBINSON: "Rocket-boosted action, brilliant speculation, and the recreation of a horror out of the mythologic past, all seamlessly blend into a rollercoaster ride of suspense and adventure." -- James Rollins, New York Times bestselling author of JAKE RANSOM AND THE SKULL KING'S SHADOW "With THRESHOLD Jeremy Robinson goes pedal to the metal into very dark territory. Fast-paced, action-packed and wonderfully creepy! Highly recommended!" --Jonathan Maberry, NY Times bestselling author of ROT & RUIN "Jeremy Robinson is the next James Rollins" -- Chris Kuzneski, NY Times bestselling author of THE SECRET CROWN "If you like thrillers original, unpredictable and chock-full of action, you are going to love Jeremy Robinson..."-- Stephen Coonts, NY Times bestselling author of DEEP BLACK: ARCTIC GOLD "How do you find an original story idea in the crowded action-thriller genre? Two words: Jeremy Robinson." -- Scott Sigler, NY Times Bestselling author of ANCESTOR "There's nothing timid about Robinson as he drops his readers off the cliff without a parachute and somehow manages to catch us an inch or two from doom." -- Jeff Long, New York Times bestselling author of THE DESCENT PRAISE FOR ELLIS: "Some books are just plain unbridled fun, others are edge of the seat gripping entertainment, some make you think, a few open your eyes, Sean Ellis is a magician, doing it all with a deftness that pulls you in and draws you along from page one breathlessly to the end of the book." -- Steven Savile, author of the international bestseller, SILVER "Sean Ellis delivers another high-octane romp, exploring mythical lost civilizations and alternative histories, with the unrelenting pace of your favorite summer blockbuster." --Stel Pavlou, bestselling author of DECIPHER ABOUT THE AUTHORS: JEREMY ROBINSON is the author of eleven novels including PULSE, INSTINCT, and THRESHOLD the first three books in his exciting Jack Sigler series. His novels have been translated into nine languages. He lives in New Hampshire with his wife and three children. SEAN ELLIS is the author of several novels. He is a veteran of Operation Enduring Freedom, and has a Bachelor of Science degree in Natural Resources Policy from Oregon State University. He lives in Arizona, where he divides his time between writing, adventure sports, and trying to figure out how to save the world.