What is a short summary of Dahl's, William and Mary, from the short-story collection, Kiss Kiss?

In William and Mary, after Mary's controlling husband William dies of cancer, his scientist friend Landy, extracts his brain and eyeball. He keeps William's brain and eyeball alive using a mechanical heart. When Mary goes to see William in his new form, she is delighted by this version of her husband. Finally, she has power over him.