This hour, we walk the tightrope between doubt and certainty, and wonder if there's a way to make yourself at home on that razor's edge between definitely...and not so sure.

We meet a geologist whose life is rocked by a crisis of faith, talk to a gambler who's made a name (and millions) by embracing what she can't know, and we relive a series of decisions and convictions that turn one woman's certainty into a deeply troubling question about just how certain is certain enough.

NOTE: This episode contains graphic descriptions of sexual assault and violence.