Hitchhiker's: Mostly Harmless Ending

I finished all the books, but I barely remember the ending.  Agrajag dies again.  Ford is laughing like a maniac.  But then Arthur is about to die, somehow..?  I don't remember.  Refresh my memory.

What bothered me the most was Fenchurch's disappearance.  Felt it was a sloppy way to get rid of a character.