Mysterious Stranger

"As Colin Cole hunts his old enemy, across what was left of America, I hunt Colin Cole."

-Mysterious Stranger, narrating the opening scene of Episode 5: Retribution

"You point a six-shooter at someone, you better be ready to pull the trigger."

Mysterious Stranger to Colin Cole

About
The Mysterious Stranger is aptly named, because he is extremely mysterious. There is a great deal of mystery surrounding the character, and very little is known about him.

Timeline
The Mysterious Stranger is a minor character in Episode 5: Retribution. Nothing is known about him up until he appears in Episode 5, other than the fact that he had a perceived debt to Colin Cole for some mysterious reason.

Episode 5: Retribution
He somehow tracked Colin Cole to the Quarantine Zone during the chemical attack by Travis Tuckins. Eventually, after trailing Colin Cole for an unknown amount of time, he witnessed Colin intervening in the conflict between Butch and the Abusive Hobo. When the Hobo pointed a weapon at Colin Cole, the Stranger decided than it was time to reveal himself to Colin by killing the Hobo. After the Hobo was dealt with, the Stranger explained to Colin that his debt was payed. With that, the Mysterious Stranger disappeared, never to be seen again.

Appearances
The Mysterious Stranger appears in only one episode.
 * Episode 5: Retribution - Minor Supporting Character

Trivia

 * The Mysterious Stranger's actual identity has been debated by fans. The most popular theory is that he was Colin's Uncle, Sal Mondini. This has not been confirmed in any way.