Gwen arrives at the hub to find a stranger there but everyone else seems to know him.  When he touches her, she remembers him as always being a part of Torchwood.  Later, when she arrives home, she doesn't recognize Rhys.  Things begin to add up for Jack as hidden memories surface and Adam appears to be behind it all.  He discovers that Adam is not what he appears and that he must have memories of him instilled in the group in order to survive.