 Joan Summers (Louise Currie) enters the office of jewel merchant Montclaire (Francis Pierlot) closely followed by Kendal Wolf (Kent Taylor). Each recognizes the other to be a jewel thief, and wordlessly they team together to steal a $30,000 diamond. Searched and questioned when the gem is missed, they are released....with the gem. Detective Sharpe (Larry Blake) is still suspicious and so is the head of Jeweler s Indemnity, who puts two underworld men on to retrieve the diamond. Kendal agrees to meet the two but the police are tipped and Sharpe confiscates the gem and the fence s money. Again Kendal and Joan are released, but each suspects the other of being an informer despite a growing romantic attachment. Kendal and Joan attend an exhibition of the Malabar diamonds, leave to follow a diamond-lade guest, overtake her car, shoot the chauffeur and slug the woman. At Kendal s apartment, Joan makes it clear that robbery, not murder, is her game. Two men and the robbed couple arrive and reveal the whole thing to be a hoax to test whether Joan will work with the gang and to assure them she wasn t the informer in the first theft.