a little help, please

i love alfred hitchcock movies. i even loved lifeboat.
i've seen bits and pieces of vertigo, but had never seen the entire thing, so when i saw it coming up on AMC, i set my DVR to record. yesterday i sat down to watch it, and before it was over, the recording ended.
needless to say, i shouted a few choice expletives at my television.

i feel robbed.

so here's my question - can someone tell me what i missed? i don't even know how much i missed. (for those of you who haven't yet seen it, please stop reading now. i don't want to be responsible for spoiling.) it had just gotten to the point where scottie and judy went up to the top of the belltower and the nun came up and scared judy and she fell off the ledge.
i would wait for it to come on AMC again, but it isn't scheduled until the 6th, and netflix would take entirely too long.
someone please enlighten me.
thank you.