Over the years, the Pathfinders - distinguished by the fact of their each being the sole survivor of the apocalypse on different parallel Earths - have become a tight-knit team, exploreing alternate Earths in the hopes of finding one to which they, and the Authority, might one day evacuate. Now one has been found: an untrammelled Eden on which humanity never evolved. But just when their job seems over, three new threats emerge: one is an old, if unexpected, enemy; another comes from within the Authority itself; while a third is so completely unexpected that the Pathfinders are quickly overwhelmed. Can Jerry, Rozalia, Nadia, Yuichi and the others face up to this final threat - or has their luck finally run out?