In post-WWII San Francisco, Dune House is an oddity-a sprawling, heavily-gated mansion with no telephone, no radio, and no electricity. The city is abuzz when it learns that Julia Paget, the rich, reclusive mistress of Dune House, is conducting a search for her long-lost heir.

When newly-engaged Lark Williams visits Dune House to find the truth, Julia Paget forbids her from leaving. As Lark plans her treacherous escape, she uncovers several unnerving secrets. The tragic drowning of Julia Paget's sister decades earlier. An enigmatic cousin named Benson Drew. Opera music being sung outside underneath the moonlight. The mysterious photograph that could reveal the most shocking secret of all-But first, she must get out of Dune House alive!