Castiel works for the Departure Network, a semi-legal organization dealing in assisted suicides for the terminally ill. When he’s put on Mary Winchester’s case, he meets Dean and Sam. Dean hates Mary’s decision to follow through with the plan and, by extension, hates Castiel. But, as the two get to know each other, something begins to grow between them, and Castiel finds himself breaking the first rule of his job: Don’t get attached.