Answer the following question: I am a movie director and I just received the following movie plot. Could you help me answer this question? If not, let me know by writing "Not answerable". Plot title: The Bat Whispers Movie plot: A mysterious criminal by the name of "The Bat" eludes police and then finally announces his retirement to the country. In the countryside near the town of Oakdale, news of a bank robbery in Oakdale has put Mrs. Van Gordner's maid, Lizzie, on edge. Mrs. Van Gordner is leasing the house from Mr. Fleming, the Oakdale bank president, who is in Europe. The chief suspect in the bank robbery, a cashier, has disappeared. Mrs. Van Gordner's niece, Dale arrives followed by the gardener she has hired. Dr. Venrees arrives and tell Mrs. Van Gordner that he has received a telegram from Fleming stating that because of the robbery he will be returning soon and will need to occupy his house. There are mysterious noises in the house and lights turning on and off. A rock is thrown the window with a note threatening harm if the occupants don't leave. Dale, and the gardener, who is actually Brook, the missing teller, are looking for a secret room in the house. They believe the money from the robbery is hidden there. Detective Anderson shows up and questions Mrs. Van Gordner. Mr. Fleming's nephew, Richard, arrives at Dale's request. She is hoping he can help in finding the secret room. Richard finds the house plans but refuses to show them to Dale. He pushes her away and runs up the stairs but he is shot by someone at the top of the stairs and falls dead. Mrs. Van Gordner sends for a private detective. A mysterious masked man sticks a gun in the caretaker's back and tell him he better get everyone out of the house. The lights continue to go on and off. The shadow of the Bat is seen by various occupants of the house. Anderson states that Fleming isn't in Europe but robbed his own bank. He accuses the doctor of being part of the plot. An unconscious man is found in the garage. He comes to and is questioned by Anderson. He can't remember anything. Anderson tells the private detective to keep an eye on him. The hidden room and the missing money are found. Fleming, the missing banker, is found dead behind a wall in the... My question: What does Mrs. Van Gordner send for?
Answer:
A private detective