The bad guy on this episode is a bad girl. And the actress who plays the bad girl is a bad ass in the gym. Figure competitor physique - noticeably muscular physique and a set of abs that don't quit. Off-season.
Further research reveals it to be Stacy Haiduk, who played Lana Lang on the old Superboy TV show, the more recent Heroes and also as a regular on All My Children.
The episode is playing a lot over the next week or ten days, so check your local listings. She looks niiiiize.
Nice to know she's still around.