Who is Robert Agar from The Great Train Robbery and what is their importance?

Agar grew up working in a match stick factory, which left him with permanent lung damage. As an adult, he began working as a screwsman, someone who makes copies of keys for the purpose of criminal acts. Pierce hires Agar to work with him on the Great Train Robbery.

Agar doesn't know the details of the crime Pierce is planning, but he manages to pull of an amazing feat by making several copies of the two keys kept in the railway office in less than a minute. Agar is then placed in the van with safes on the day of the robbery. In the end, however, Agar's girlfriend rats out the group and causes them to go to jail. Agar is sent to Australia, where he becomes a wealthy man. His son will later become the mayor of Sydney.