When the Doctor investigates a too-good-to-be-true diet pill, he runs into his old friend, Donna Noble, and a strange alien breeding program. The plan involves slowly converting the overweight of London into children of the Adipose, but it breaks intergalactic law. Will London be overrun with cuddly babies made of human fat? Will Donna Noble travel with the Doctor? Will the hired goons survive?
Justin finally meets Donna Noble, and Erik explains Penny Carter, the companion who almost was. Both get lost when Justin invokes the film, Boiler Room. They also consider introducing a companion on the Hindenburg and how the Doctor would take to traveling with Hugh Glass. Justin is forced to confront Billie Piper, and Erik declares, once again, that he doesn't hate David Tennant or the Tenth Doctor. Not that the readers of Rotten Tomatoes will believe that. The Shadow Proclamation gets a name check, and Justin recalls the Ghostbusters Role Playing Game.