It was very Classic Who. I love that it’s “single story” again. Oh I missed single stories with cliffhanger.
The friends (companions) are richly fleshed out and believable already. Felt an actual “oh no!”. Two youngest companions are stretching the “we’re 19, really!” a little bit but British TV never cared about that.
It works. Also glad she was inspired by Doc Brown: That angle fits well.