Complex sentence: When Bond leaves Benz and Kerim Bey alone together, Grant kills them, and makes it appear as though they killed each other, preventing Bond from leaving the train with Romanova to rendezvous with one of Kerim's men.
Split into simpler sentences: When Bond leaves Benz and Kerim Bey alone together, Grant kills them, and makes it appear as though they killed each other. This prevents Bond from leaving the train with Romanova to rendezvous with one of Kerim's men.