Prohibited from seeing her actor sweetheart Herman Brandt by her tyrannical parents, sweet young Vienesse lass Mariette defies authority by regularly visiting Brandt's downstairs apartment. The lovers' signal is a song called "The Firebird," which Brandt sings whenever he wants Mariette to visit him. When the actor is murdered, poor Mariette and her parents are prime suspects. But the truth is a bit more complicated than that, involving as it does a haughty aristocrat, a powerful diplomat and a most unusual "candid camera" device.

A very nervous man named Cartwright comes into Perry's office to have the neighbor arrested for his howling dog. He states that the howling is a sign that there is a death in the neighborhood. He also wants a will written giving his estate to the lady living at the neighbors house. It is all very mysterious and by the next day, his will is changed and Cartwright is missing, as is the lady of the house next door. Perry has a will and a retainer and must find out whether he has a client or a beneficiary.