A mysterious stain appears on the wall in one of the rooms of a guest house located in the Athenian Riviera, run by the young Alkistis and her mother, Anna. Their only guests are Petros, a failed writer who can no longer afford to stay there, and the Chatzivassileiou couple, their most loyal clients, who threaten to leave due to the growing mold in the house. Meanwhile, Alkistis tries to communicate with a dying tree, and her best friend, in disbelief, tries to make her more extroverted. The young woman gets involved in a doomed romance with a local builder. Meanwhile, Anna is trying to decide whether to sell the guesthouse.

"Riviera" makes its world premiere at the 48th Mostra.