Image: Postcard of the Bahia Honda Bridge, Key West, Florida, 1930-1945. The Boston Public Library.

As scores of people head to the shore for the weekend, we’re summering with “Islamorada,” Rivka Keren’s taut story of a Florida Keys vacation turned moral test. In the island town of the title, a bickering couple, Ernest and Amalia, are interrupted by a young man bursting into their hotel room. He’s not a robber but a Cuban refugee, the survivor of a capsized smuggler’s boat, with the US Coast Guard hot on his heels. Amalia, already on edge, flatly says they should turn him in, but when the officers arrive to search the room, Ernest hides the fugitive and claims no knowledge. After the lawmen leave, Ernest, playing for time, introduces himself as a professor of Spanish literature and asks the youth if he knows Don Quixote. The young man responds by addressing Amalia as Dulcinea and reciting a courtly speech from the book. When the astonished Ernest asks if he’s a literature student, the boy explains that his grandfather, an illiterate cigar roller, knew Don Quixote by heart and encouraged him to memorize it as well. Now he wants to reach the house of a friend of his grandfather’s, in Tampa; can he walk there? “Not on foot, and not on horseback,” sneers Amalia; but after discovering that he and the Cuban share an even more improbable connection, Ernest turns modern-day knight errant, jousting with the law and his disaffected wife in the quest for the young man’s safe harbor. It’s a fresh twist on the notion of beach reading, and a welcome reminder of the power of our shared literary culture.