After three wars, the fleets of Earth are far from home, strung out along a narrow path leading to the worlds of Gree and Jagar's Retreat. With their worst nightmare realized, they have no choice but to turn about and race back the way they came. Many systems back, communications were cut. Earth is unaware of what approaches. Emma travels in the opposite direction, seeking help from the only race that can stop humanity's latest enemy, or so she believes. On the world of Draylun, she leaves Niko and Abby to fend for themselves or find their own way home. What they discover in the process will amaze and bewilder all. Having liberated the people of Jagar's Retreat, Naomi and her team come face-to-face with the same race that has terrorized Union space for over a thousand years. Outbound 4: Odyssey's Torch is the final book of the series.