Comrade (2006)

Ilan, an adolescent boy who lives in a farming community, is in constant clash with his father. He accidentally finds a stack of letters in the house attic, letters from his sister Dalya, that never reached him. Through these letters he learns the story of his sister's disappearance, and some facts about his life and his deceased mother.
He decides to run away to his sister. A complex relationship develops between the two. Ilan gets closer and closer to his sister's eccentric neighbor. The neighbor, an aging communist with a grand military past, runs, with Ilan's help, a battle against the authorities.
The story starts as a conventional adolescent drama but quickly turns into a fascinating and unexpected maturing journey.