Mr. Smith is the Mission Coordinator and right hand of Mr. Jones, chief of UNITY. Prior to this position, Mr. Smith served as a UNITY field agent for many years before "volunteering" to move to an administrative position. Mr. Smith lived in a flat in London.
Believing that Bruno Lawrie was too old for the field, Mr. Smith was campaigning to move Agent Lawrie into an administrative position. When the lack of available resources forced his hand, he was finally forced to start assigning Cate Archer to various missions as UNITY's first female operative.
On one of his last missions, Mr. Smith met Melvin Blitzny in Florida. Mr. Smith (using the alias of Mr. X) started grooming Blitzny to be a possible double agent between UNITY and H.A.R.M. in a revenge filled scheme. Mr. Smith had a secret bank account in Zurich where he hid his money he was getting from H.A.R.M.
In the final cutscene of The Operative: No One Lives Forever it is revealed Mr. Smith was the traitor all along, possibly tipping off H.A.R.M. about the nature of each assignment of Cate Archer (which would explain the heavy resistance and high alertness everywhere), After shooting Melvin Blitzny, who was posing as Tom Goodman, he himself is shot by Mr. Jones. Wounded, he tries to reach for his gun to kill Bruno Lawrie, he is killed by Cate with a single shot from hers.