Probably the 4th or 5th time I've watched this first episode and it's never any less astonishing

I love the rotating cast of Number Twos

but

also

I wish there were 17 episodes with Leo McKern as Number Two

I kind of legitimately miss how tv shows used to re-use the same clip all the time for some special effect sequence, it makes it kind of a little ritual
I like that we get a Number Two who is sweating bullets because of pressure from above

Hidden steel door embedded in a rocky cliff face

you can't tell me this show wasn't a direct influence on Lost