Lyric discussion by Malmo 

Cover art for Failsafe lyrics by New Pornographers, The

I'm hearing bolt, too. It changes the meaning of the song entirely.

It sounds like it's about two partners in crime (or perhaps the two lovers in Challengers eloping), facing the obstacles (scolding the hills ahead), changing their identity (singing my checks), etc.

One person, the speaker, gives up (lost half the team) and finds the other still going, scolding the hills alone, and probably feels guilty for leaving.

Weird interpretation, I know, but the song is pretty weird, too.