Descender Volume 4: Orbital Mechanics

Tim-21, Telsa and Quon finally escape the Machine Moon and head out on a quest to find the ancient robot who may hold the key to the Harvesters. Meanwhile Andy and his rag-tag team close in on Tim, but their fragile alliance is shattered by Driller's revealtions.
A new chapter of the heartfelt Sci Fi epic begins here by superstar creators JEFF LEMIRE and DUSTIN NGUYEN
Collects issues 17 through 21.