10 Dumb Decisions In Doctor Who We Can't Forget
8. Adam Mitchell's Head Implant - The Long Game
Adam Mitchell was initially conceived, according to former showrunner Russell T Davies, to be an example of a companion who failed the Doctor and got thrown out of the TARDIS as a result. Well, it's safe to say that Adam fits that bill. He's first introduced in the Season One episode, "Dalek" and proves himself to be a cowardly and ineffective individual who only makes it into the TARDIS at all when Rose Tyler begs the Ninth Doctor to let him aboard.
His brief stint on the show is basically one long dumb decision, but his crowning moment of idiocy comes in the following episode 'The Long Game'. Despite the Doctor's warnings, Adam decides to get an implant in his head that can open and expose his brain whenever he clicks his fingers.
He then tries to use this implant to send knowledge about Earth's future back to its past, again defying the Doctor's advice, allowing the monster of the week to access vital information about the Doctor and Rose.
Adam was so stupid that he literally nearly got Rose and the Doctor killed on his first and only trip in time and space. Nice going.