S3·E8 Shattered

Lex locates Morgan Edge and gets him to admit to dirty dealings with Lionel, but before Lex can take it to the authorities, someone tries to kill him at the mansion. Barely surviving, Lex flees and asks Clark for help. However, when Clark returns to the mansion to investigate he finds nothing amiss, and begins to wonder if it really happened, especially after Lionel announces Lex has had a psychotic break and must be institutionalized.