FBI agent Topolsky returns to warn Liz that a covert alien hunter inside the Bureau is pursuing Max and his friends -- and that he will stop at nothing to get what he wants. Meanwhile, Isabel befriends Tess, a new female student who immediately arouses Max and Michael's suspicions.
Casts:
Shiri Appleby, Jason Behr, Katherine Heigl, Majandra Delfino, Brendan Fehr, Nick Wechsler, Adam Rodriguez, William Sadler