When William Duncan, a wealthy man who became the leader of a band of thieves for the thrill of committing burglaries, is betrayed by his gang members and sentenced to spend 25 years in prison, his twin daughters, Doris and Dorcas, disguise themselves as the mysterious Madam Madcap to carry out a revenge against the men who framed their father!

 

A thrilling story of mystery and adventure by Johnston McCulley, the creator of Zorro!