No One Is Safe.

There's a new corporation in town -- Meta-chem -- and Liz is psyched to land a scholarship program working in the lab. But when the giant pharmaceutical company creates a disease that accidentally infects the town, Liz is among the first to fall ill -- and, despite his powers, Max is unable to heal her.

There's also a new girl in town, Sadie, who's come to Roswell searching for her half sister, who she believes is Maria. Maria doesn't know how to feel: what if she and Sadie do share a father? Maria hasn't seen him since she was seven years old, and she's not sure she wants to see him now. but when news of the quarantine breaks, Maria has no choice but to keep Sadie with her in town, all while trying to find out who is sick and whether anyone can be saved in time....