Nestor wants to go live with his sister in the US, nevertheless, he is the only one who lives with his mother and he can't leave her alone.

Spain, 1937. Ramón Mercader, a young communist combatant, is recruited and trained by the Soviet intelligence service to participate in a top secret mission ordered by the ruthless dictator Joseph Stalin: the assassination of his former political rival, Leon Trotsky, who is living in exile in Mexico.