Episode 84

Firstly, roving gangs, killer machines, cannibal grannies, and an undying architect plague The Doctor and Mel ("Paradise Towers"). Then genocidal mercenaries hunt an alien queen to Earth, in an effort to destroy her and her rapidly growing spawn ("Delta and the Bannermen"). And lastly, a dragon holds the key to an icy madman's freedom ("Dragonfire"). Additionally, Dan teaches Mike a new word, Mel leaves The Doctor to take up with Sabalom Glitz, Ace debuts, and Dan believes the 24th season just might be the worst ever.