Please answer the following question: Given the following context:  Norman Sterns and Leela Sterns are newlyweds who are driving from their home in New York City to Los Angeles. They become lost and run out of gas, stranding them in the rural Ozark countryside. They meet a friendly paleontologist named Wayne Thomas. Wayne suggests that they visit the nearest farm that could provide gas. The farm is run by a strange man named Greely, who tells them that the gasoline truck was supposed to arrive the previous day, but since it didn't, he expects it there any minute. Greely suggests that they go inside to the parlor, where it's cooler. On the way up to the house, he asks if they know anybody out here, in case they may be waiting for them. They say no, and when they get inside, Greely goes off to tell his "housekeeper", Bella to make some iced tea. She argues with him on what he will "do with them", but Greely smacks her, and threatens that she will "take their place" if she doesn't serve them some tea. Thomas arrives and Greely goes outside. He tells them that their car won't start. Wayne decides to take a look at the engine and tells Greely to go back to his truck and get a tool. Greely instead beats him on the back of the head with it and drags his body off. Meanwhile, Leela appears to be worried about Greely, because he is acting strange and his eyes don't look right. She then compares his eyes to a stuffed lizard across the room. Greely comes back inside and tells them that he had to do a chore. Leela wants to go back outside, but Greely tells them that they could check out his "collection" while waiting for the truck.  answer the following question:  What does Greely use to beat Wayne Thomas on the back of his head?
Answer:
a tool