The show begins by introducing three recently deceased sinners: Sinnerman, Heresy, and Marionette. They are sorted by the Angels - both disillusioned by humanity - to go to Heaven or to the Underworld. The sinners are chosen to travel with the Angel and get assigned to the Circle that best suits their life choices.

Cut to Satan - caught in an eternity long love affair with an Angel of Heaven. His struggle between his duty and his love has caused his personality to split. 

As the sinners travel through the Underworld, the Angel strays away from her duty and decides to keep the sinners safe. This creates consequences for all four. 
Cut to Treachery - each sinner presents their reasons for redemption to Satan and their fate is decided.