The Jailbirds are reeling after a devastating standoff with Orion in Peru, but the mystery that began with Tommy at Hollow Hill isn't over. More determined than ever to finish what Tommy's father started, Mars recruits a new source to help him uncover Orion's true motives while Maya pulls at an old thread - one that just might unravel the secrets and lies that have plagued their lives. Both haunted by the sins of their fathers, Jude wrestles with a decision about his future while Reid struggles to come to grips with his past. Meanwhile, in South America, Immy works to fulfill a promise made to her parents when the arrival of familiar faces thrusts her into danger and leads to a fifteen-year-old unsolved murder.

A world of secrets will be exposed. Family ties will unravel. Deadly betrayals will come to light. With Orion hot on their tail, the Jailbirds follow a new trail of clues across the country to the small, New England town of Mariner's Cove, Maine. Daring escapes, hidden messages, and stolen fossils all converge as the Jailbirds face their most desperate challenge yet: the fight for family.