Tonight’s Episode: Chapter 16, Unexpected

Peter (Milo Ventimiglia) painfully learns that someone close may have betrayed him and Claude (guest star Christopher Eccleston). Matt�s (Greg Grunberg) world spirals out of control when radioactive man Ted Sprague (guest star Matthew John Armstrong) and Hana Gitelman (guest star Stana Katic), a fierce young woman with �wireless� mental abilities, drop into his life. After blood is spilled, Hiro (Golden Globe nominee Masi Oka) makes a difficult decision about his mission. Claire (Hayden Panettiere) is unable to contain her anger at her father (Jack Coleman).

Tawny Cypress, Santiago Cabrera, Noah Gray-Cabey, Ali Larter, Adrian Pasdar, Sendhil Ramamurthy and Leonard Roberts also star. Jimmy Jean-Louis, Lisa Lackey, James Kyson Lee, Zachary Quinto and Cristine Rose guest-star.