Lost is a show of wide, sweeping spaces. In any given episode, the ever-moving camera will zoom in on characters from Los Angeles to New Zealand who are separated by as much as 30 years. However, with the exception of flashbacks, the drama between young Ben and Sayid in "He's Our You" played out almost entirely in a tiny underground cell.
The show has made use of this Kafka-esque claustrophobia before; Jack and Ben's respective imprisonments in the first few seasons come to mind. But in "He's Our You," the tight, no-breathing-room setting is the perfect accompaniment to Sayid's tormented struggles with what he is, and what Ben will become.
In that small room, Sayid finally sees a glimpse into Ben's early life, before the lies and manipulation. He sees an unhappy child, probably the butt of classicism with his janitor father, and most definitely the victim of abuse. Although Sayid is literally behind bars, Ben is just as trapped. He's forced to stay in the village, away from the vast breathing room of the jungle and he's tied to a violent father. He wants out.
Meanwhile, Sayid wrestles with his own destructive past, wondering if (adult) Ben was correct when he told him, "It's in your nature. You're a killer." Remembering all the murders he performed for Ben, Sayid begins to suspect he was right.
However, just as the dungeon closes in on the two trapped characters, Sayid closes in on himself in this episode. Other than flashbacks, the audience really has no idea what is going on behind his stoic expression. We are given clues that perhaps he is repentant for what he's done, and will die to pay penance for all those he's killed, such as when he meets the island's "coerce master" to extract information from him and Sawyer tells him "he's our you." The dungeon seems to grow tighter and darker as young Ben's discontent grows and Sayid broods. Then, when the friction between them is so palpable you can feel it, you see Sayid's true intention. The tension is dissolved with a gunshot, in the night air, in the open jungle.
Sayid runs off, and a young Ben lies alone, perhaps fatally wounded. The question remains: Can anything these characters do change the future?

Great analysis/summary. This show is so well-written.