Unspoiled! The Constant: Lost

We learn what's going on with Desmond since the Hatch Explosion and it's sort of what Krista was thinking: he's seeing the future. But it's Charlie's future, and the outlook's not good. He also flashed into his own consciousness in 1996 when he was moving in with Penny and hoping to marry her. He meets a mysterious lady, has weird memories of The Island, and throws it all away as he's...destined to do?