Isn't it amazing that Lucas hallunicate and saw Kate and Will. But knew exactly what they were going to say about Sami. For Kate said that Sami has deserted him but Will say that Sami is coming back. I think it is because Kate hates Sami and Will knows that his mother will never left his dad there to die. And maybe Will knows how much Sami loves Lucas and knew that Sami could never be that cruel. And at least gave Sami the benefit of the doubt.