The 5th book in the time-travel series featuring 3 children from different points in history who should have died, but who find themselves working for an agency no one knows exists. This time, they have to put history right again after Project Exodus, a mission to transport 300 Americans from 2070 to 54AD to overthrow the Roman Empire, goes terribly wrong. The first book in the series won the Red House Book Award. Ages: 11+