The Fonz keeps his cool after a clerical error lands him and his 4-F knee in an Army reserves training camp just before little Heather's birthday; but he doesn't know that his commanding officer is someone he knows...and hates...all too well, and who believes that he finally has Fonzie right where he's always wanted him.

An unexpected surprise waits for him at the church when Fonzie agrees to be former Falcon's gang member Jake 'Hey Fonz' Nelson's best man at his second wedding; Howard and Marion help K.C. rehearse for her school play audition.