(S07E19) Lex is still pursuing the secret of Veritas. In his journeys, he encounters a cloaked stranger who tries to kill him and later on tries to kill Clark. I think this episode borrowed a page or two from The DaVinci Code. For that matter, I think half the season did.

Lex has been hurt or nearly killed a great deal since the start of this series. It's unlikely his latest chest mutilation will ever heal. It wouldn't surprise me if he left the area of Smallville entirely. Oh, wait...