The play opens with a balletic prologue, half-danced, and half-mimed, showing the growing resentment between the Jets, a gang of white “American” boys, and the Sharks, a Puerto Rican gang. Lt Schrank and Officer Krupke, fed up with all the violence on their beat, chase the Sharks away, leaving the Jets to plot a “rumble” with the Sharks (“Prologue”). The Jets’ leader, Riff, plans to challenge the Shark’s leader, Bernardo, at the dance that evening. He then plans to convince his best friend Tony, a former Jet who is trying to keep on the straight and narrow, that he should join the gang at the dance. Despite some doubts that Tony will remain loyal to the gang, Riff assures the other Jets that he’s here to stay (“Jet Song”). Riff meets Tony at Doc’s Drugstore, where he’s been working, and though Tony initially refuses, Riff eventually prevails. Tony, leaving the drugstore, feels that that evening will be the beginning of something (“Something’s Coming”).
Meanwhile, Maria, a recent immigrant from Puerto Rico, is working in Anita’s bridal shop. Maria is betrothed to Chino, a friend of her brother Bernardo’s, but confesses to Anita that she does not love him. Anita remakes Maria’s communion dress into a stunning gown to wear to the dance that night.
At the gym, which has been converted into a ragtag dancehall, the Jets and the