Complex sentence: Balveda, now exposed as a Culture agent, in turn exposes Horza; seeing no reason to continue his deception, he instead recruits the remnants of the crew to carry out his mission.
Split into simpler sentences: Balveda, now exposed as a Culture agent, in turn exposes Horza. He sees no reason to continue the deception and instead recruits the remnants of the crew to carry out his mission.