Fringe/Recap/S01 E10

Season 1, Episode 10:

Safe
A team of thieves, led by Mitchell Loeb, is stealing safety deposit boxes from banks by walking through the walls. However, when one of the thieves gets stuck in the wall and killed, the rest of the group leave him behind. The Fringe team is called in to investigate and Olivia believes that she recognises the dead thief, only to later realise that it's actually John Scott who knew the thief and that his memories are continuing to surface in her mind. The team tries to determine what was in the safety deposit boxes, only for Walter to realise that it's a teleportation device that he invented and hid away. Meanwhile, Nina Sharp and the Massive Dynamics team "interrogating" John Scott realise that some of his memories are gone. As the Fringe team tries to track down the thieves, Loeb uses the teleportation device to break David Robert Jones out of prison, while at the same time ZFT operatives abduct Olivia.