Task: Question Generation
Input (English): Passage: Private detective Humphrey Campbell tracks down a runaway woman, Louise, and ends up marrying her. On the way to Reno, Nevada, for their honeymoon, the couple stop at a bank, which is robbed by three men. 
Humphrey's employer, Oscar Flack of the Flack Missing Persons Bureau, tracks the newlyweds to a Reno hotel. (Across from the hotel, Louise spots an odd advertising clock, which has no hands. This has no bearing on anything, however.) Oscar wants him to find a missing man, Hal Benedict. Louise convinces him to take the case after Oscar promises her a fur coat for locating Hal. They go to see Warren Benedict, Hal's father. When Humphrey learns the FBI may be involved, he wants nothing to do with the case, but Oscar gets him to change his mind. Humphrey tries to keep Louise out of danger, but she has other ideas and keeps tagging along.
In the hotel bar, Humphrey learns that Hal was often seen with a woman, a redhead named Irene Donovan. A blonde named "Gypsy" Toland offers him a ride to Irene's place, but when Humphrey is spotted by a furious Louise, he gets out of the car. Humphrey later finds Irene dead. He also finds a very much alive Rose Madden, Hal's fiancée, who protests that she did not kill Irene. They drive off in Rose's car, then park and start talking. Louise spots him with the brunette Rose. Louise is ready to walk out on Humphrey, but the police will not let her leave because her husband is now a murder suspect. 
Humphrey goes to see Clyde Copley, a collections investigator who admits he was hired by Hal to retrieve letters Hal wrote to Irene; Irene had threatened to use them if he married Rose Madden. Humphrey is cleared of the murder when Police Chief Bates learns that he has a solid alibi.
Output (English): What is the last name of the person who wants Humphrey to find a missing man?