During a rebellion of prisoners at the San Quentin State Prison, Boston Blackie makes a lightning escape aided by Mary McGinn while chased prison guards. Mary is a school girl, unaware that her brothers are crooks. She is expelled from school. Blackie rejoins his gang and takes refuge in Mother McGinn's house, where he again meets Mary. She devotes herself to making Blackie go straight and wins her point.
Colleen Moore
as Mary McGinn
Forrest Stanley
as Boston Blackie
Margaret Seddon
as Mother McGinn
Hobart Bosworth
as Warden
George Cooper
as Travel
Eddie Phillips
as The 'Glad Rag' Kid
Wade Boteler
as Detective O'Leary
Tom Bates
as Sandy
Carmelita Geraghty
as Ethel Grayson
Maxine Elliott Hicks
as
