The hospital co-workers find it difficult when Josh's sister comes looking for him and Aidan can't be around blood.
Peter Farragut, Sarah Jordan and Dr. Kyle Sommer go to a mysterious island to investigate an unknown pathogen that killed everyone, except Leila, aboard the Mist of Avalon.
Sally asks the pair to invite her fiancé to come round; meanwhile, Aidan receives some startling news and a hungry Rebecca ambushes Josh.
Sally gets some ideas about how to make Danny's life miserable from a poltergeist; meanwhile, Josh's sister stays over.
Josh's family reunion is a disaster, Aidan fights for his friends' safety and Sally loses Bridget to Danny.