Freddie Threepwood, still trying to persuade his Aunt Georgiana of the benefits of Donaldson's Dog-Joy, hears that his cousin Gertrude has become infatuated with Orlo Watkins, a weedy tenor invited to the castle by Lady Constance. While visiting his friend Beefy Bingham to borrow his dog Bottles, Freddie learns that she has indeed all but "handed him the bird".
Freddie tells this to Lady Georgiana, while giving a rather poor demonstration of Dog-Joy's powers, during which Bottles is scared off by Susan, one of Lady Georgiana's Pekes. He later tries to reason with his cousin, but to no avail; the glamour of the singer has taken her over.
That evening, while the household take after-dinner coffee in the drawing room, Freddie enters with Bottles and a sack of rats, intending to demonstrate the Dog-Joy reared mongrel's ratcatching prowess; Orlo Watkins, observed by Gertrude, cringes somewhat at the sight. The family protest, and Beach is called to take the bag of rats away. Bottles remains, however, and when one of Lady Georgiana's Airedales comes in, a mighty battle commences.
Watkins, to Gertrude's disgust, leaps atop a display cabinet, while the others dither about. Just in time, Bingham enters, sees the fight in progress, and breaks it up by the simple expedient of taking one dog in each massive hand and pulling. His manly display shakes the scales from Gertrude's eyes, and she falls into his arms, while Watkins slinks off, defeated.
Lady Georgiana, meanwhile, is so impressed by Bottles' performance that she orders two tons of Dog-Joy off Freddie.