The Doctor manages to escape from BOSS with help from Yates and discovers Cliff has been infected by a giant maggot.
Quest roles:
Richard Franklin(Mike Yates), Nicholas Courtney(Brig. Lethbridge-Stewart), Roy Skelton(Daleks (voice)), John Levene(Sergeant Benton), Jerome Willis(Stevens), Stewart Bevan(Clifford Jones), John Dearth(Lupton), Mitzi McKenzie(Mrs. Martin)