This episode is a lot different than the ones before and takes it to a whole new level. It's not so much House's hallucinations, but this episode does a great job of showing us the weight of things. It revolves around death: Chase's remorse, Wilson's dead girlfriend... I think it shows that the season is slowly, reaaaalllly slowly moving into a darker direction. Hugh Laurie's performance is simply breathtaking in every scene, and as it turns out a sane, drug free House, appears to be way darker and human than the cracked up maniac before. Although some events, especially in the beginning of the episode may seem like a jigsaw puzzle hammered together, it all makes sense in the end. Really nice episode.