S3, E9: Lex languishes in the sterile confines of Belle Reve Sanitarium, where his father has placed him. Scheming to escape and prove his sanity, Lex gets involved with three inmates who are also vengeful former residents of Smallville: murderous Van McNulty (recurring guest star JESSE METCALFE); Eric Summers (recurring guest star SHAWN ASHMORE), who once temporarily gained Clark's powers; and Ian Randall (recurring guest star JONATHAN TAYLOR THOMAS), who can physically split himself into two people. Meanwhile, Clark tries desperately to help Lex, who now knows Clark's secret identity. And Lana begins the painful recovery process after being trampled by a horse. She finds a kindred spirit in a determined fellow patient, Adam (recurring guest star IAN SOMERHALDER).