In Ireland, Peter attempts to move beyond the past, but discovers that a mysterious woman -- Elle -- is willing to kill to find him. Matt and an unexpected ally fly to Philadelphia to hunt down the nightmare man, following his terrible attack on Molly, but the pair finds themselves outmatched. Monica tries to come to terms with her new abilities and her role as a local hero. Suresh meets his new partner and gets a disturbing assignment. H.R.G. takes a step to further protect his family. Meanwhile, as Hiro continues to fix the past in feudal Japan, Ando attempts to piece together historically what's happened to his best friend.