In this comedy, New York City undergoes a dramatic change when a toucan carrying a strange virus is smuggled through customs. In those it infects, the virus causes an intense euphoria and a desire to do good. The first man to receive the infected bird is a misanthropic, cynical artist who lives in an apartment with his girlfriend. The couple names the toucan "Amigo," and soon they are indeed happy. They decide to spread it around and so the bird is freed. The Big Apple goes into an economic tailspin as its residents become deliriously happy and stop buying cigarettes, booze and tranquilizers. To save the financially foundering city, the mayor and a presidential envoy begin distributing unpleasant masks to the happy city-dwellers. The artist and friends thwart the officials' scheme by infecting the masks. So begins a battle between the officials and the artist. Eventually Amigo is caught, and an antidote is delivered. The renowned rudeness, cruelty and selfishness of the native New Yorkers quickly returns, and the city is saved. The artist realizes that his quest has been futile, and he devotes the rest of his time and energy to making his girlfriend happy.