S4, E15: H.R.G. (Jack Coleman) recruits Matt (Greg Grunberg) to help him take down Samuel (Robert Knepper), as they use his long-lost love, Vanessa (guest star Kate Vernon), to lure him to them, but Samuel has his own plans for Vanessa in the works. Meanwhile, Hiro (Masi Oka) and Ando (James Kyson Lee) go to extreme lengths to save Dr. Suresh (Sendhil Ramamurthy). Elsewhere, Peter’s (Milo Ventimiglia) introduction of Emma (guest star Deanne Bray) to his mother (Cristine Rose) brings forth visions of a very grim future. Hayden Panettiere also stars. Todd Stashwick and Sasha Pieterse also guest star.