The U.S.S. Enterprise must pass through the quadrant Korona IV, which is inhabited by the Jarada, an insect-like race that demands a precise greeting from the Captain of any ship wishing to enter their territory.
Taking a break from the difficult greeting preparations with the Jarada, Captain Picard visits 1941 San Francisco in the fabricated environment of the holodeck. He is soon joined by Data, Dr. Crusher and Whalen, the ship's historian. But when the holodeck malfunctions, the four crew members are trapped in a 20th century murder adventure in which Whalen is killed and Picard, Data and Crusher are held at gunpoint by gangsters.
While Wesley Crusher struggles to repair the holodeck and get the kidnapped crew back to the ship, the Jarada threaten to prevent the U.S.S. Enterprise from traveling through their quadrant unless they are greeted by the Captain ... in one hour!
As Wesley's repairs near completion, the passageway back to the starship begins to materialize. Picard tricks two of the three criminals into entering the passageway, where their fabricated images instantly dematerialize in a real environment. After a brief skirmish with Picard, the third criminal is felled by Data. Upon returning safely to the ship, Picard successfully executes the Jaradan greeting, allowing the U.S.S. Enterprise to pass through without incident.