The second series continues the plot from the first, which ended with Dr. Caroline Todd (Greig) and Dr. "Mac" Macartney (Rhind-Tutt) falling in love, and he, Dr. Guy Secretan (Mangan) and Dr. Martin Dear (Karl Theobald) teetering over the edge of a cliff in a stolen ambulance after Guy has a nervous breakdown. The second series starts with Mac in a coma and Guy having to perform community service as punishment for stealing the ambulance. When Mac awakes from his coma, it is discovered that he has amnesia, meaning that he has no memory of his relationship with Caroline. As Caroline tries to make him remember, Mac's former girlfriend Holly Hawkes (Sally Phillips) returns to the hospital, claiming that he is the father of her son. Elsewhere in the hospital, Dr. Alan Statham (Mark Heap) and Joanna Clore (Pippa Haywood) become paranoid after they accidentally murder Joanna's dwarf cousin.