A midget criminal, Calvin, and his partner steal the Queen's Diamond, a very respected and valuable diamond in the museum. The museum guards activate the alarm so the criminals are on the run. They try to hide in a grocery store. Calvin takes the diamond and puts it in a man's bag. The man exits the grocery store and goes home. To get the diamond back, the criminals cook up a plan to get it back. Calvin has to act as the man's new son. The man just so happens to be an anxious wannabe dad.