Aqua

A summer beach party at Crater Lake takes a dramatic turn when Lois hits her head while jumping into the lake. Before Clark can save her, a mysterious swimmer named AC (Alan Ritchson) comes to her rescue, out-swimming Clark and leaving him baffled. Professor Fine (James Marsters) tells Clark that Lex is behind a covert weapons manufacturing operation. AC breaks into a LuthorCorp facility in an attempt to destroy one of Lex's dangerous experiments and is captured by Lex.

Season 5 | Episode 4
Cast

Allison Mack

as Chloe Sullivan

Annette O'Toole

as Martha Kent

Erica Durance

as Lois Lane

John Schneider

as Jonathan Kent

Kristin Kreuk

as Lana Lang

Michael Rosenbaum

as Lex Luthor

Tom Welling

as Clark Kent