The Apocalypse Script. The Nisirtu

Ben Mitchell is having a very bad year. He has no clients, no money, no love life, and a lot of bills. Worse, the world is going to hell. Armies are on the move, the stock market is crashing, crops are failing, and a deadly pandemic, Cage's Disease, is sweeping the globe. The researcher finally catches a break when a wealthy and beautiful client, Lillian Stratton, offers him a job deciphering several mysterious, ancient tablets.
The assignment promises to bring him wealth and fame. Perhaps even romance. There are a few conditions, however. To study the tablets, the researcher will have to travel to Steepleguard, a massive and nearly abandoned hotel hidden deep in the Rocky Mountains. He must also join the Delphic Order of the Nisirtu, a powerful and ruthless secret society with some very peculiar membership requirements. His sponsors? A delusional, self-proclaimed "princess, " a killer wanted by the police, and an ancient man who speaks in riddles.
Ben soon finds himself a pawn in an international game with the highest possible stakes. Trapped by his supposedly benevolent hosts, he learns that everything he's been told is a lie and that the motives for bringing him to Steepleguard are far more sinister than he could have ever imagined. Ben thought he had nothing to lose. He was wrong. He has everything to lose, including his life. To escape Steepleguard, the researcher must defeat the Nisirtu at their own game.
But even as he plots his escape, he discovers that a far greater enemy lurks beyond the gates.