Ruben Greavy was a member of the Rapture population and was one of the head engineers of Rapture, originally under the management of the Wales brothers. He was an ardent supporter of Andrew Ryan and Ryanist Philosophies. Ryan also regarded him as a loyal friend and "a true Renaissance man." Greavy often worked with Bill McDonagh on engineering and maintenance projects within Rapture and was a memeber of Rapture Central Council.
Greavy met his death in 1955 when, while walking near the entrance to Fontaine's Home for the Poor in Apollo Square with Bill on routine maintenance, he was run through with a screwdriver from Bill's toolbox, wielded by a telekinetic Splicer.