|No||Code||Title||Air Date||Eps||Exists||147||7D||Time and the Rani||07 Sep 1987||4||All|
|148||7E||Paradise Towers||05 Oct 1987||4||All|
|149||7F||Delta and the Bannermen||02 Nov 1987||4||All|
|150||7G||Dragonfire||23 Nov 1987||3||All|
Quite when Melanie became a companion is not explained, she was a companion in a vision of the Future during the Trial of a Timelord and suddenly appeared at the end of it in the present time. Melanie leaves and Ace joins during Dragonfire. Just what happened to the Doctor to cause him to regenerate into his seventh persona, played by Sylvester McCoy, is not made clear.
Time and the Rani
Still unstable from his regeneration at the end of the trial, the Doctor is deceived by the Rani into believing she is his companion, and she tricks him into helping her build a powerful new weapon. Meantime, Mel is on the run and befriends the meek enslaved population of the planet on which the Rani is making the Doctor work for her.
The Doctor and Mel land in a giant tower block now in a degenerate state of decay, with its inhabitants grouped into warring factions. The whole is presided over by a megalomaniac caretaker, who seeks the destruction of all the inhabitants. Can the Doctor persuade the factions to unite against the common enemy and his killing machines?
Delta and the Bannermen
The Doctor and Mel encounter a space craft that looks like a 1950s bus, which is taking tourists to visit Disneyland. Unfortunately, the Chimeron Queen Delta is on board the bus, escaping from a band of murderous mercenaries (the Bannermen) who were hired to destroy the Chimeron race. After a Bannerman attack on the space bus, it crash lands in a South Wales holiday camp called Shangri-La. After Delta escapes, the Bannermen attack again, killing all the tourists. Can the Doctor save her with the aid of a young mechanic, a local bee keeper and 2 US secret service agents?
The Doctor and Mel arrive on Ice World, a deep space trading post and are reunited with Sabbalom Glitz who joins them in search of the mythical Dragon. Mel befriends a waitress called Ace who is rather keen on explosives. The Doctor finds the Dragon and collects the power crystal from it, but is forced to give it to the crazed ruler of Ice World, Kane, in order to save Ace's life.