At Sixes and Sevens

Rhianon and Sabrina Webster are born into a humble mining community. Their stern father dotes on his youngest daughter, beautiful, flighty Sabrina, but it is homely, Rhianon, who strives to keep their family together - until the day when the man she loves, Pryce Pritchard, is involved in a fight, accidentally kills Sabrina's boyfriend, and is sent to jail. Sabrina runs away from home because she is pregnant and Rhianon finds her living in squalid conditions in a Cardiff slum. When the baby is born it is Rhianon who cares for him until Pryce is due to be released from prison after three long years and then Sabrina tells her that the child is his - which of them will he return to?