This is a precode. William is Bob, an x-ray technician whose nurse girlfriend (Jean Muir) gives him the money to complete medical school - $1500 - you couldn't get in the door for that today. He manages to gamble it away before he can even get there, but he returns a year later, supposedly a doctor.
Fate steps in when he meets a morphine addict who is an ex-doctor. In exchange for morphine, the addict hands over his medical license. Bob changes his name and starts practicing in New York City, with his erstwhile girlfriend as his nurse. I forget how he explains the name change but she believes him. He brings on a real doctor (Donald Meeks) who actually diagnoses the patients. He's also somewhat of an inventor, having come up with a process that brings the dead back to life.
Bob isn't actually interested in anything like illness - he wants the society crowd where the women want to be charmed.
Trouble follows - the morphine addict keeps darkening his door, and he gets stuck with some real sickness he has to cure.
Short, enjoyable, with William playing the lovable cad to perfection.