Sydney races to find a cure for Vaughn, but in order to find the antidote, Sydney must make a deal with Sark that could endanger Sloane's life. Meanwhile, Will continues his research for Vaughn and discovers some disturbing inconsistencies involving ... (more)20-year-old standardized IQ tests.

Austin Tichenor, Chris Ellis, Ivan Borodin, Jim Hanna, Joel Guggenheim, Mak Takano, Michelle Arthur, Peggy Goss, Petra Wright, Reamy Hall, Stephen Davies, Stephen Mendillo, Terry O'Quinn, Victor McCay