Seething over Keith Hernedez's success with women, George becomes convinced that Hernandez's sexual power over women resides in his mustache. George carefully steals the mustache with a pair of scissors when Hernandez falls asleep on Jerry's toilet. George then goes around town wearing Keith's mustache to mixed and surprising results.
Kramer and Jerry discover their true feelings for each other, hastily get married (after creating a new concept in marriage: the "man-marriage" which they hammer out as a Platonic arrangement centered around sports- appreciation and the institution of the "shared refrigerator") .
And finally to utterly confound, surprise, and dismay the audience, Larry David left the Elaine character out completely.
Also: the actor Wayne Knight, a.k.a. Newman was forced to lose 200 pounds
for the last episode by Jerry and Larry who confined him to an abandoned
missile silo in upstate New York to effect the crash weight loss. Newman was
skinnier than Kramer ! Wayne Knight has apparently been passing himself off
in a fat suit recently, and successfully concealing his new appearance.
How Newman's thinness works into the final plot I can't remember as I
was completely smash-face-pasted when I saw it. (No, I was not at the show and
was travelling from Hong-Kong to Beijing- incredibly there are a few boot leg
tapes of this last episode - but all of them are somehow mysteriously and
exclusively in the hands of a few Chinese passenger-freighter crews who sail
the Far East.)