Man, I loved that one. Midnight was great in a similar way but was missing the companion, Heaven Sent only had the Doctor and Don’t Blink had hardly any Doctor or the companion in it. This is finally a great bottle episode that is only the Doctor and his companion.
RTD at his best, if this is an indication of his new era I can’t wait. And the way he managed to make the whole Flux and Timeless Child thing mean something emotionally almost as a bonus - must sting for Chibnall watching it, who completely failed to do the same thing having an entire season for it