Happy Ending by Henry Kuttner — Read

This is the way the story ended:

James Kelvin concentrated very hard on the thought of the chemist with the red mustache who had promised him a million dollars. It was simply a matter of tuning in on the man's brain, establishing a rapport. He had done it before. Now it was more important than ever that he do it this one last time. He pressed the button on the gadget the robot had given him, and thought hard.