An edgy janitor takes Clark's high school class hostage at LuthorCorp, claiming his jitters were caused by a mysterious contaminant.
When Junior is kidnapped as leverage to retrieve the stolen list of undercover CIA agents, Tani and Quinn ask Magnum and Higgins for their help.
Reed, Caitlin and Lauren chat with a doctor who treats patients with debilitating X genes, but Lauren finds out something more about the doctor; after the Inner Circle's bank ambush, Thunderbird and Blink continue to track them down.
Tensions within the Inner Circle continue to soar as Andy comes to Rebecca's defence against Reeva; Lauren attempts to convince Reed and Caitlin that they must get rid of Dr Risman's research; Jace strategises with the Purifiers.