So dark and disturbing- so when I say that "I found this so hard to read" you'll realise it's a compliment. It took me a while to figure out why Sam was doing what he was doing when he so clearly was an unwitting victim. Lucifer's dream was an inspired, if horrifying, piece of writing - spot on characterisation. Let's only hope that Sam inside Lucifer's head is as debilitating as Lucifer inside Sam's was!