10 Dumb Decisions In Doctor Who We Can't Forget
2. Bill Potts Just Leaving The Doctor's Body - The Doctor Falls
The last two episodes of Season Ten, 'World Enough and Time' and 'The Doctor Falls', are not only considered by most fans to be the Twelfth Doctor's finest hour, but also often ranked as the best series finale in the show's entire history. And with good reason.
There's the thrill of seeing both John Simm's Master and Michelle Gomez's Missy team up, there's Peter Capaldi giving the best performance of his run, and the Cybermen are perhaps the most menacing they've been since the Tenth Planet way back in 1966. In fact, the episode begins with companion Bill Potts having been converted into a Cyberman.
Don't worry. She gets better thanks to some intervention from her immortal, space-hopping girlfriend from earlier in the series.
The dumb decision comes when Bill, despite having declared just minutes earlier that she can't just leave the Doctor behind... leaves the Doctor behind in the TARDIS. Our poor Time Lord wakes up thinking that Bill is still a Cyberman and with very little idea as to how he ended up back in the TARDIS.
It might have been nice for Bill to stick around for a little while to tell her best friend what was going on, wouldn't you think?