Lewis Venable, an ambitious publisher, travels to Venice in search of lost love letters written by the famous poet Jeffrey Ashton. Disguising himself as a writer named William Burton, he lodges at an old mansion owned by the reclusive Juliana Borderau and her protective niece, Tina. Juliana, whose past romance with Ashton forms the basis of Lewis's quest, is now aged and guarded by Tina, who is suspicious of the new tenant. Despite this, Lewis uses his charm and persistence to get closer to the hidden letters he desperately wants to publish.

As Lewis digs deeper into the mansion and its secrets, he finds himself increasingly entangled in the lives of Juliana and Tina. The atmosphere in the mansion grows tense, underscored by strange occurrences and haunting memories of the past. While trying to gain access to Juliana's treasures, Lewis starts developing unexpected feelings, complicating his mission. His professional objectives clash with personal emotions, leading to a series of revelations that unearth old wounds and hidden truths.