* ORPHAN BLACK. 9 p.m. Saturday, BBC America.

Send in the clones: Tatiana Maslany (below) remains the hardest-working women in TV as the Peabody Award-winning sci-fi thriller, in which Maslany plays multiple, utterly distinct characters, begins its second season.

* BILLY CRYSTAL 700 SUNDAYS. 9 p.m. Saturday, HBO.

The comedian's Tony-winning one-man show, taped in January, is a love letter to his father (who died when Crystal was 15), to jazz and to his '50s childhood in Long Beach, N.Y.

* APPLE MORTGAGE CAKE. 7 p.m. Sunday, Uptv.

Kimberly Elise stars as a single mother trying to save her home with the help of an old family recipe in this sweet but not saccharine TV movie based on a north Jersey woman's true story. Fans can also see Elise this weekend opposite Whoopi Goldberg in "A Day Late and a Dollar Short" (8 p.m. Saturday, Lifetime).

* DEVIOUS MAIDS. 10 p.m. Sunday, Lifetime.

University of the Arts grad Ana Ortiz isn't masquerading as the help anymore, but "Maids" - and "Desperate Housewives" - creator Marc Cherry found a way to keep her at the center of the action. Eva Longoria directed the Season 2 opener.

* SIGNED, SEALED, DELIVERED. 8 p.m. Sunday, Hallmark.

Valerie Harper guest-stars (and sings and dances) as a U.S. Postal Service legend in the premiere of this whimsical series about dead-letter office "detectives."