S4, E5: Samuel (Robert Knepper) prepares for new additions to his family, while Lydia (guest star Dawn Olivieri) warns him of the consequences. Claire (Hayden Panettiere) discovers that her roommate Gretchen (guest star Madeline Zima) may have a hidden agenda. Meanwhile, Peter (Milo Ventimiglia) finds an unexpected way to connect with Emma (guest star Deanne Bray), who would prefer to stay distant. Elsewhere, a different side of Sylar (Zachary Quinto) emerges as he desperately tries to remember the person he used to be. Masi Oka and Cristine Rose also star. Rachel Melvin and Jack Wallace also guest star.