Smallville Season 8 episode 16

In this episode, Tess Mercer devises a plan which will reveal Clark's true identity, while Davis comes up with a plan to ease the demon within him, but finds himself trying to scramble after Jimmy sees him kill someone.
In previous episodes, Lana was back at Smallville and with special armor that looks like a second skin, she has Clark's powers. Unfortunately, this armor absorbs kryptonite and stores it. Lana has absorbed too much kryptonite, and this being dangerous for Clark, she had to leave by abandoning the one she loves the most ... Clark