The family of Henrietta Winslow gathers at her stately home, in
anticipation of her seemingly imminent death. Thinking that the
elderly woman has already passed away, real estate agent A.
Gilmore "Gil" Smith and antique dealer Mr. Penny arrive at the
Winslow estate, only to be refused entrance by gardener Eduardo
and housekeeper Abigail Doone. While Gil and Penny watch from
outside, the invalid Henrietta appears before her family to read
She bequeaths her niece, Myrna Hartley, $100,000, and
Myrna's husband Montague and stepson Richard $10,000 each. She
then gives her granddaughter, Margaret Gordon, and grandson,
Stanley Grayville, $100,000 each, while leaving her home and the
remainder of the estate to her favorite granddaughter, Elaine
Winslow (Anne Gwynne).
Outside, Gil begins to cough because the horde of cats
Henrietta has living on her estate have triggered his allergies,
and thus discovered, he and Penny are invited into the house. An
upset Henrietta realizes that Montague has sent for Gil to sell
the estate, and she tells the real estate man that she will never
sell. After Gil saves Henrietta's life when he realizes that her
milk has been poisoned, she reveals the last, unread portion of
her will: No one will get any money until Abigail, the guardian of
the estate, has died. Henrietta is then murdered while cremating a
When a black cat suddenly appears, an hysterical
Abigail tells Gil and Elaine that it symbolizes death. Convinced
that Henrietta's death was accidental, the family gathers together
in hopes of settling the estate, while Gil tries to convince
Abigail that her life is in danger. The housekeeper orders the
family to leave the estate, but they refuse and send Montague into
town to seek legal representation. Richard, however, discovers his
father is having an affair with Margaret and threatens to go to
his beloved stepmother unless he leaves his mistress.
meanwhile, finds an unconscious Abigail while searching for
antiques. Gil and Elaine question the injured housekeeper, who
finally begins to realize the threat on her life. That night, Gil
tells the family that there must be secret passageways in the
house that his hypothetical murderer must have used. After
numerous false alarms throughout the night, Abigail is discovered
hanged in her room, and Gil finally manages to prove that the
housekeeper was murdered.
Myrna is seemingly attacked in the same
manner, but is saved by Gil, Montague and Richard. Believing him
to be the killer, the men chase after Eduardo, who is then killed
by Myrna. Later, Elaine accuses Myrna of the killings and of
staging her own attack in order to gain her inheritance and thus
keep her husband. Myrna knocks Elaine out, then hides her body in
the closet just as the men return.
As Myrna prepares to burn
Elaine to death in the crematorium, Gil bursts in and saves her.
The black cat then knocks over a candle, setting Myrna afire. With
the murderer uncovered, Gil and Elaine are finally united, and she
agrees to sell the estate.