The king and his ministers are all extremely obese and spend much of their time playing practical jokes. They especially enjoy laughing at and abusing Hop-Frog. Even his name is the result of their making fun of the way he walks.
A masquerade ball is planned for the next night and Hop-Frog is expected to come up with costumes and a practical joke that the king and his ministers can play on the rest of the guests. Hop-Frog hesitates, and the king forces him to drink wine, which Hop-Frog despises. When Trippetta tries to intervene on Hop-Frog's behalf, the king knocks her to the floor and dumps wine in her face. This angers Hop-Frog and he suddenly comes up with a trick the king and his ministers can play on the masquerade guests.
The plan is to dress the king and his ministers up like ourang-outangs and suddenly invade the party frightening the guests. The king thinks it is a marvelous idea. Hop-Frog dresses them in tight-fitting clothing, paints them with tar and applies flax to simulate hair. As a final touch Hop-Frog chains them all together. On the king's orders all ballroom doors are locked and the key is given to Hop-Frog. After the beasts have entered, Hop-Frog is to lock the final door so the frightened guests cannot escape.
On the stroke of midnight, the beasts invade the ballroom, causing havoc. As though playing along with the game, Hop-Frog attaches their chain to the chandelier chain. (The chandelier having been removed