According to Michael Ausiello of Entertainment Weekly, various sources aren't mincing words:
Two key characters will die in this May's season finale.
And, no, these won't be pretend, Heroes-like deaths: a pair of lives truly will come to an end.
"These characters will die and they will stay dead," said a Smallville insider. "This is the real deal."
Let the guessing begin. Who do you think it will be?