Smallville - Season 4 Episode 12 -

When Lana is attacked in her apartment and Jason in his car by an invisible being, everyone believes that Alicia Baker was responsible, except Clark. However after a series of circumstances, Clark begins to doubt Alicia's innocence to the mysterious attacks. Alicia tells Clark that she'll offer to prove her innocence if Clark reveals his own superpowers, but Clark refuses. So, Alicia secretly shows Chloe the abilities of Clark, expecting people to leave them both alone. But elsewhere, Lois discovers that the real culprit of the attacks is the deranged Tim Westcott ...