F - 342/6 - The Doomsday Key (Sigma Force #6) by James Rollins

At Princeton University, a famed geneticist dies inside a biohazard lab. In Rome, a Vatican archaeologist is found dead in St. Peter's Basilica. In Africa, a U.S. senator's son is slain outside a Red Cross camp. The three murders on three continents bear a horrifying connection: all the victims are marked by a Druidic pagan cross burned into their flesh.

The bizarre murders thrust Commander Gray Pierce and Sigma Force into a race against time to solve a riddle going back centuries, to a ghastly crime against humanity hidden within a cryptic medieval codex. The first clue is discovered inside a mummified corpse buried in an English peat bog -- a gruesome secret that threatens America and the world.

ID: F - 342/6