The resistance's ancient biological fail-safe — seed systems meant to reboot life across the galaxy, unwittingly triggered by later species.
The Primal Engines are the resistance's doomsday-insurance answer to the collective's genocidal weapon: a biological fail-safe, described as 'life rafts,' designed to spread seeds across the galaxy and create sustainable habitats should all life die and the collective experiment starve. Per the AI's parade history, the resistance began but never finished deploying them before the nine-tier attack. Ages later, new species — the mantids and, eventually, the crawlers' forebears — stumbled into the dormant tunnel system, exploited the sleeping Eulogist, and then 'tripped open the resistance's ancient let's-restart-life system,' flipping every switch in a house that still had power.
The Engines seeded the baby oceans that grew mudskippers into cultures, unwittingly restarting the very cycle the collective died to end.
Ancient galaxy-spanning seed-and-habitat systems — infrastructure rather than a single object; no concrete form shown.
The resistance's ancient life-rebooting fail-safe, accidentally reactivated to reseed the galaxy with life.