Complex sentence: Remembering that his attacker began unscrewing the grating over the air vent prior to the attack, he removes the cover to discover several dust-laden objects, including a few toys, a hair clip and a high school class ring.
Split into simpler sentences: Remembering that his attacker began unscrewing the grating over the air vent prior to the attack, he removes the cover to discover what lies within it. He finds several dust-laden objects including a few toys, a hairclip and a high school class ring.