 As of the end of "Ghost Story", he is told that a parasite kept his heart beating not only just after he was shot, but also while he was healing.In "Cold Days" Harry learns that some point soon, the parasite will eventually burst forth from his skull and kill him unless Molly assists him seeing how Mab deliberately kept the two apart.In "Skin Game", it is revealed that when Lash died, in an act of love (love being a form of creation) from saving Harry, the remains of her spirit joined with his to create a new spirit of intellect as their "daughter."