Complex sentence: Danny contrives to smuggle Mary on board, and during the voyage, he tries to keep her hidden, but the truth eventually comes out and Danny is hauled before Colonel Ashley--who has him sent to the brig.
Split into simpler sentences: Danny contrives to smuggle Mary on board, and during the voyage he tries to keep her hidden. But the truth eventually comes out and Danny is hauled before Colonel Ashley--who has him sent to the brig.