June 25, 1957: Sam leaps into Al Calavicci to prevent the death of his married lover. But when Sam accidentally alters history, and finds out too late about her untimely demise, it could mean the gas chamber for Al and disturbingly a whole new situation at Project Quantum Leap.

When Rab is released from prison, and Mary doesn't want him back, he moves in with Jamesie and begins to have flashbacks to his days at school and his first love Isobel.