When Mel skips school to visit her mother's grave (she won't explain why at first) her teacher Mr Coleman decides it's time to pay a home a visit. Meanwhile, Brian has developed an allergy that causes him to sneeze and morph uncontrollably. Mel starts training Sophie to behave like a 'real' mother, while Lucy attempts to diagnose Brian's allergy. Unfortunately, during his visit Mr Coleman sees Brian sprout a new nose and ears, and resolves to return with their social worker. Josh is determined to hold a party to improve his social standing – could this somehow save the whole family from being taken back into care? Will the world find out Brian and Sophie are aliens?

Lucy and Wendy are on the verge of falling out, as Wendy is upset that Lucy never invites her to her house. They arrange a sleepover, and Sophie and Brian must act as normal as possible. Meanwhile, Josh is charging Sophie for doing chores around the house so that he can later buy a snooker table.