Marcel is a spirit. Apparently, that doesn't mean he's dead, which he's more than a little grateful for. He's still stuck in ghost form, though, and he has no idea what happened or how to fix it.
Will never knew he was a psychic, but it looks like he's been seeing dead people without realizing it. Now he does, and he's going to use everything he can to help save Marcel, his best friend's brother.
But no one knows what happened to Marcel or where he is. Even when they realize someone has cast Marcel out of his body to steal his life energy, it doesn't put them closer to finding him.
They have limited time before Marcel's life energy is gone and he dies—for real this time.