Elena finally learned the truth about Stefan on "The Vampire Diaries." And in the closing moments of the episode, the safe Silas trapped Stefan in turned up. It wasn't in the quarry where Silas had put it, and its contents weren't what Damon expected to find.
“Stefan’s been in there for three months. Chances are he’s hungry," Liz said. That's why she didn't want to be the one to open it.
Damon opened the safe, but instead of finding Stefan, they found a drained body. "Well you’re right, he was hungry," Damon said. "I bet he still is.”