A story that begins with the heroine meeting her bad end at the chopping block. It can only go uphill from here, right?
Waking up after a long stay in purgatory (that she remembers nothing about), she learns that the rest of her sentence is to serve as a Reaper until the powers above have decided she's paid back her sins.
Through her journey after death as a Reaper, she'll seek out the empty gaps in her memory and reconcile her past with her present. Everyone has something to hide, and unfortunately for them, she's the type to seek out answers. But the biggest challenge for the crew will be to save her from herself.
Or they might all just get a one way ticket to Hell. At best.