From the Alternate Universe, Mark Wilner is small-time thief and the accomplice of Joshua Rose. Both of them broke into an Amber quarentine zone in Franklyn Street Station to release Joshua's twin brother Matthew Rose, who had been accidently incarcerated when he was trying to warn his brother that the Fringe division was on to his illegal activities. Because of the breach new Amber gas was released to reseal the area, and while both brothers made their escape, Mark couldn't get away in time and got trapped in the Amber.