Olivia's sister, Rachel, visits; Walter, Peter and Olivia try to solve the murder of an esteemed epidemiologist, which may be linked to Olivia's abduction.
Quest roles:
Ari Graynor(Rachel), Trini Alvarado, Chance Kelly(Mitchell Loeb), Michael Gaston(Sanford Harris), Stephen Schnetzer, Peter J. Fernandez(Dr. Simon)