This year’s first disinterment at the Rossini Opera Festival is the composer’s 1819 Ermione, which flopped at its Naples première and has languished in comparative neglect ever since. Historians consider it one of the composer’s most startling masterpieces and, on Sunday night, it was easy to see why.

Ermione, based on Racine’s account of the tragic Andromaque, investigates the fatal love triangle between Achilles’ son, Pyrrhus; Menelaus’s daughter, Hermione; and Hector’s widow, the Trojan Andromache. Rossini attacked the subject with gusto, using the clean techniques of French opera and was thoroughly misunderstood by his contemporary public for his pains. Today, distance allows us to appreciate the stormy drama and tense, taut architecture of this thriller.