Reminds me of the bit in Apollo 13 where Jim Lovell is talking about when he was a fighter pilot, and his instrumentation started failing (or something) so he couldn't communicate with the aircraft carrier, and then all his lights go out. Which would normally be an absolute disaster but this time it's what saves him, because he has no exterior lights, he can see the phosphorescent algae churned up in the wake of the carrier, so he can follow that home.
It's the last line he says that stays with me:
"Who knows what events will transpire to bring you home"