Corrected entry: Riley, the former Borg, says that she was assimilated at the battle of Wolf 359. This is impossible, since there was only one Borg ship at the battle, and it was heading straight for Earth, and when it finally got there, it was destroyed.
Correction: Presumably the Wolf 359 cube launched a sphere like the one in First Contact before it was destroyed but out of view of the Enterprise-D which then returned to the Delta Quadrant via transwarp.
Correction: To quote the Borg Queen from First Contact, "You think in such three-dimensional terms." She was on that very same ship and she survived. Surely she escaped with at least a small contingient of her drones. They don't tell us how, but it is rather clear that some sort of time travel was implimented.
Garlonuss ★