After a year as civilian, old Nash is back in SFPD's SIU to investigate a series of "unrelated" murders.

Rory MacNeil, a rugged old Scotsman, travels to San Francisco to seek medical treatment. He moves in with his estranged son Ian, as he sees his life getting transformed through a newfound bond with his baby grandson.

Aliens who look like clowns come from outer space and terrorize a small town.