Kevin McNulty

Mulder and Scully search for a humanoid killer whose savage murder spree reoccurs every thirty years.

Alicia is assigned her first case after having to return to work following her husband's corruption scandal and incarceration. She quickly discovers that the retrial of a woman accused of murdering her ex-husband is not as straightforward as it seems.

When Clark rescues his classmate, Eric Summers (Shawn Ashmore), from harm during an electrical storm, they are both struck by lightning -- resulting in all of Clark's superpowers being transferred to Eric. While Eric relishes his new life as "Superboy," he soon begins to abuse his new powers. Clark's happiness at finally being a "normal" teenager is tempered by his growing concern for the town's safety. Meanwhile, Lex confronts Clark, believing that he has undeniable proof of Clark's superpowers.

Mulder and Scully pursue an unbalanced scientist whose research has caused his shadow to become deadly.

Scully learns new details about her sister's murder as Mulder pursues the shapeless alien entity inside Krycek's body.