When Will invites Lily to meet his grandmother at the Saint Catherine Laboure care home for witches, she learns the residents have been dying at an alarming rate. Will's grandmother is scared she'll be next-but they put it down to the paranoid ramblings of a dementia patient. Until Will's grandmother dies unexpectedly for no apparent reason…. To find the killer, Angelica volunteers to go undercover, being one of the only older agents in the PIB. Lily's magic reveals her mentor is in mortal danger, but despite Lily's arguments, Angelica takes the assignment. Can Lily use her witchy skills to unravel the mystery before someone she loves becomes the next victim?