Joshua Rose is a character from the Alternate Universe and a reformed bank robber who traded places with his twin brother Matthew Rose after triggering an Amber quarentine that encased his brother for four years.
He used to rob banks using Negative Matter Rings, unintentionally causing micro breaches that had to be contained by Fringe Division by implementing Amber quarentine zones. Learning that the Fringe Division was on to his brother's illegal activities, Matthew tried to warn him when he was out robbing a bank, accidently getting trapped in the Amber. The whole world was unware that Joshua had successfully escaped and had assumed his brother's identity, living with his sister-in-law Danielle and taking care of his two nephews. Ashamed of what he had done to his brother and other innocent people, he tried to come up with a way to break Matthew out of the Amber.
After four years, Joshua and his accomplice Mark Wilner broke into the Amber quarentine zone in Franklyn Street Station to retrieve Matthew from the Amber, and managed to revive him with several resuscitation techniques. Because of the breach new Amber gas was released to reseal the area. Unfortunately, Mark couldn't get away in time while both brothers made their escape.
He takes his brother home to his family, and helps him recover enough to resume his life with his wife and kids. During the course of the investigation, Joshua greets the Fringe Divion investigators posing as his brother, but Olivia is able to see through his elaborate deception.
Afraid that they'll discover about the identity switch, Joshua comes up with plan to redeem himself. He breaks into Riverdale Mutual, and again his brother finds out the blueprints and follows him there. Not seeing any tools, he realizes his brother's real plan and tries to talk him out of it. Joshua insists that the only way they'll ever leave Matthew alone is if someone is caught, or else they'll keep on trying to find him. He says that if they do they'll keep him away from his family to experiment on him as he is the only known person that has been encased in Amber and survived.
The Fringe Division finally quarantines the zone, encasing Joshua in the Amber in suspended animation, while his brother escapes successfully.