Complex sentence: Peter realizes he had been bitten and would too be cursed to become the werewolf, but instead of killing him, Valerie helps him dump Cesaire's body in the lake and Peter rows away, leaving Valerie behind.
Split into simpler sentences: Peter realizes he had been bitten and too would be cursed to become the werewolf. Instead of killing him, he and Valerie dump Cesaire's body in the lake and Peter rows away, leaving Valerie behind.