A shapeshifter infiltrates the team by pretending to be Harrison. Not a bad episode but it was quite obvious who the shapeshifter had turned into towards the end of the episode.
In front of Matthew See, Karen Gillan takes off Billie Piper's bikini, Karen then takes off Jenna Coleman's bikini, Billie and Jenna then takes off Karen's bikini. All are now showing their tits to Matthew as he kisses all three of them and sucks their tits.