Big Steve Halloway, gambler and proprietor of New York's Horseshoe Cabaret, is in desperate need of money. He arranges for his fellow bookies, especially Sorrowful Jones, to each pay him $1,000 for his racehorse, Dream Prince, to lose. With all bets being placed at the window, Sorrowful encounters a gambler, having lost $500, wanting to place his bet but unable to come up with $20. Instead, he places his little girl, Marthy Jane, as security, or in bookie's terms a "marker". "Marky", as she comes to be known, winds up under the care of Sorrowful Jones and his lady friend, singer Bangles Carson.
