- "That guy's got bigger problems than Valenti and the FBI put together"
- ―Michael to Isabel about Max and Liz
Suspicions about the new girl, Tess, are further raised when everyone notices Max is oddly drawn to her. Unable to fight his attraction, Max kisses Tess not knowing Liz is watching in the distance. Max attempts to explain the kiss to Liz as something he had no control over, which raises Liz's own suspicions about Tess's identity. Isabel and Michael each explore Tess's identity, but neither can prove she is anything but a normal high school student. After Michael and Max discover a hidden video camera in Michael's apartment, they think it might have come from Tess.
Liz decides to take the camera to hide in Tess's home. There she meets Tess's strange father, ED HARDING, who insists Liz stay for dinner. As Liz strategically places the camera, she breaks a precious statue. Michael, Isabel, Maria and Alex watch as the camera goes blank. Fearing she may be in trouble, the kids go to rescue Liz from the Harding residence. After a successful rescue, the kids all watch as Tess reconstructs the statue using alien powers, revealing she is the fourth alien. Meanwhile, when Valenti checks up on Topolsky at the mental hospital he realizes she's been killed. Feeling the kids may be in real danger, Valenti decides he may be the only one to protect them. Wanting to gain their trust Valenti takes the communicator (orb) back to Max.
- Shiri Appleby as Liz Parker
- Jason Behr as Max Evans
- Colin Hanks as Alex Whitman
- Katherine Heigl as Isabel Evans
- Majandra Delfino as Maria DeLuca
- Brendan Fehr as Michael Guerin
- Nick Wechsler as Kyle Valenti
- William Sadler as Jim Valenti
- Michael Chieffo as Mr. Seligman
- Kevin Cooney as Dr. Malcolm Margolin
- Michael tells off Max about cheating on Liz and generally has Liz's back