When an unidentified flying object is spotted over Hampstead Heath, Dudley becomes obsessed with UFOs and the idea of photographing one from his bedroom window. When he disturbs daughter Jacqui's front porch romancing with her boyfriend Peter, she borrows her sister's old luminous Frisbee to play a prank on him, throwing it past his window; taking it for a UFO, he clicks his shutter. Susan, meanwhile, dons a devil costume as she practices her role as assistant to her stunt man boyfriend Vincent, alias Vince Vampire. The next day Dudley is hosing down the car when Jacqui and Vincent exit the house in costume and ride away on Vincent's motorcycle, and hoses his leg by accident. Duncan arrives with some good news; an American editor and his wife are coming to see him, and Mr. Millington is willing to inject some money into The Wowser if they feature one of his cartoon strips, which he wants Dudley to draw - and it could mean some extra money for him. The Americans are arriving on Friday,