I know! Augustine Quill tries to explain what would've happened if Cassie had traveled back in time to prevent David from becoming a traitor, to save some of the lives that were lost in the war. However... he has shared with me that David's girlfriend had sex with him... AGAINST HER WILL. So the story includes rape, and she is GOING TO GO BACK TO HIM, so that puts me off the story. Too bad. It was really good too.
But onto the topic. We'd need to know more about David's personality. And WHY he didn't go traitor. What if he formed feelings for Cassie, of the attraction sort?