Among the secrets that remained till the end of the show, Claudia got away with setting up her son Steve, which directly got him killed.
Joan Van Ark and Donna Mills return to the series for the finale.
Mack burns the tape in the fireplace, to hide the evidence from the police. Just 1 season earlier, Karen had (partially) burned Meg's birth certificate in the fireplace, to hide the evidence from Brian Johnston.
Bill Nolan compares Paige's degree on the wall with not knowing everything about business.This matches that in earlier seasons they said Paige had an arts degree, not business.