Sigma Force Commander Gray Pierce is thrust into a dangerous hunt for clues in just such a scenario when he must fly to Rome in order to help his friend Rachel Verona. It was her uncle who arranged a meeting between himself and the archaeologist inside the Vatican, a meeting that someone wanted to prevent. Now as he lays in a Rome hospital comatose from the blast Rachel wants to discover who killed the archaeologist researching the roots of Celtic Christianity and why. Her clue? A tiny satchel she recovered while snooping the crime scene. But another woman from Gray's past makes an appearance in Rome, the treacherous assassin known as Seichan. Soon the trio are fighting in the streets of Rome, including a spectacular action sequence through the Coliseum as agents of a mysterious cabal spare nothing in order to stop them in their tracks.
Rollins orchestrates other crescendos of action as battles over the Doomsday Key between the Sigma team and Guild agents are fought in, among other exotic locales, the English peat country, where a fiery apocalypse leaves the team singed but not stirred; and the frozen Norwegian wastelands, home to the Svalbard Global Seed Vault where crusty polar bears do not take too kindly to all the ruckus. In the end, treachery forces Pierce to make a choice between the woman he loves and the future of the world's food supply.
Though in some of his thrillers action seems to predominate — 2004's Ice Hunt comes to mind here — Rollins strikes an balanced approach in his latest thriller, allowing the reader some recovery time between the rough and tumble of the action. And though, for now, this is the last Sigma Force book, The Doomsday Key leaves room for more: “A war is coming,” Pierce says. Stay tuned. Rollins has surely more up his sleeve.