ETA: Still watching. Stabler is now in the bad guy's former cell, in solitary confinement. Which is sort of a neat idea, to verify for himself whether being alone in solitary is as bad as the guy who tossed him off the roof said it was, but come on now. He's a married man with children, how on earth would he have time to experiment? Secondly, we can't tell how long he's been alone but it seems a really long time and Stabler's obviously going stir-crazy. When his buddy comes to let him out, we learn he's been in solitary for three days. I figure Stabler would have gone into this experiment as sleep-deprived as most parents with young children are and would have slept away those three days. Three days does not seem nearly long enough to drive an otherwise sane person nuts, particularly when that person knows he'll be let out in just three days.
Best part of the episode? The two scenes with Detective John Munch.