Elisabetta Celestino, a brilliant young archaeologist at work in Rome's ancient catacombs, has discovered a unique pattern of astrological symbols on an underground wall. She feels sure that evidence of a previously unknown pre-Christian sect lies in an adjacent chamber, and is devastated when the Vatican refuses to support her excavation effort.

Ten years later, a cave-in damages the vault, revealing a chamber full of human skeletons that share a disturbing anatomical feature. Elisabetta has joined an Augustinian order following the tragic end of her academic career, but unexpectedly finds herself in a race to solve the secret of the catacomb and prevent an apocalyptic event that threatens the future of humankind.

Moving between present-day Europe, 1st-century Rome and Elizabethan England, The Devil Will Come is an exhilarating tale of a battle between the forces of good and evil that has been fought in the shadows through the centuries and across continents—and that both sides are willing to kill to keep secret.