The Psammy Show Season 7 Episode 2 I Wish I could see the Jester

Art & history lover, Robert wants to see a missing painting that was just found. Except that Psammy doesn't make the painting appear, but its subject : a jester. Worse, the wish did not just bring the character, it also brought the laws of painting into their world : things and people start to disappear if they come into contact with water, unless our heroes can return the jester to his painting