He noticed the way Clary’s hand would rub soothing lines up and down Simon’s back as they sat in meetings. He would watch, face hot with something like jealousy when Clary would kiss Simon’s cheek whenever she left the room. Jace saw it all. And to be honest, it was probably inevitable that he would start to watch Simon, too.

To keep the peace between the Shadowhunters and the Downworlders, a treaty designates an intermarriage between the two groups every seven years. Alec isn't exactly happy to be chosen, but then he finds out that his intended is nothing like what anyone expected.