Well. my jaw was dropped.
To the floor for 45 minutes.
After which it descended to the basement and sub-basement.
My feeling on a single viewing was that this was where this final mini-season shifted from "plot movement based on stratagems that um, might kiiiiinda plausibly work if a zillion disparate tumblers cooperated in falling into place" to "plot movement based on dueling stratagems (what were there in this episode, 4? at least 3) that APPEAR totally plausible, just some foiled and some not." Am I wrong?
And as a last note, Walt's crawling amid the rocks in what seemed like the 45:00-55:00 marks kinda reminded me of Hank Quinlan near the end of Orson Welles' Touch of Evil--not visually, just moodwise--the secretly corrupt tough guy who's called all the shots for so long, finally being hounded into a corner. Love that Touch of Evil!