Part 1 of two. Shana is back for the summer, but Matt's preoccupation with Heather delays their reunion. Robbie (Adam LaVorgna) returns to seek Mary's forgiveness and tell her he's reformed, but Eric and Annie refuse to believe it. Meanwhile, Deena breaks up with Simon for no apparent reason; Eric learns that Lucy's fallen for Robbie's step-brother; and Ruthie gets herself a boyfriend who's willing to do anything she says. Shana: Maureen Flannigan. Heather: Andrea Ferrell. Matt: Barry Watson.