(Warning: Major Spoilers Ahead)
This episode is so uneven, like a miniature version of Moffat’s tenure at Doctor Who. There are some brilliant ideas - having the Doctor bring a dinosaur along for the ride after it swallowed the Tardis - and some utterly daft ones - who wants to see an older man flail about in a nightgown? - all mixed together, but never congealing into something coherently enjoyable.
Of all the things that went wrong, though, there’s a huge missed opportunity that stands out.
Clara should have left at the end of the episode.
Imagine if she did. There’s no last-minute phone call from Matt Smith manipulating her into staying, no puppy-dog eyes from the current Doctor to beg her to stay. No. The Doctor touches down in Clara’s time, she asks if she’s home, and he says “Yes.”
He drops her off, and explains why: his past self made a mistake in thinking of her in a romantic way, and some unknown person is manipulating their relationship. Until he knows who that person is, and why they’re doing it, he’s not going to play into their plans and perpetuate his predecessor’s mistake. This is a different Doctor, a Doctor that’s not as needy, and he’s strong enough to let her go when he sees it’s best.
Making that the final scene would recast the episode as the breakup of the Doctor and Clara, giving it some emotional heft, and making his abandonment of her in the middle a kind of foreshadowing. It would also give the season a little more tension: will Clara and the Doctor ever travel together again? Will he find out who’s been manipulating them? Will he take on a new long-term companion, or will this Doctor be more independent than the past?
I feel like this approach is something an earlier Steven Moffat would have done. The writer of The Girl in the Fireplace and Forest of the Dead would have seen the opportunity for a defining, bittersweet moment, and taken it. Instead Moffat’s new Doctor, perhaps like Moffat himself, does not know when to let go.