Samantha is painting the exterior trim of the house. In an effort to help, a visiting Aunt Clara tries to conjure up a painter to do the job for her. Aunt Clara does achieve her goal, but the painter she conjures up probably can't help: Leonardo Da Vinci. Beyond the issue of Aunt Clara having problems remembering the incantation to send him back, both Samantha and Aunt Clara have a bigger problem when Leonardo decides to explore the town without telling them, which causes a few problems besides Samantha and Aunt Clara needing to find him. Meanwhile, Darrin finds out about Leonardo's arrival the hard way. It places him in a professional conundrum as one of his clients, J.P. Pritchfield, believes that Darrin's "Leonardo Da Vinci" focus is to use the Mona Lisa as the centerpiece of a new campaign for his toothpaste. Pritchfield loves the idea, while Darrin hates it. When he learns about it, Leonardo hates it even more. They have to try and convince Pritchfield not that the idea is bad, but that there is something better.
—Huggo