I think it's Jace he's trying to get back at. Jace must have
done something last night on the boat, something that really
pissed Valentine off. Pissed him off enough to abandon
whatever plan he had before and make a new one."
Luke looked baffled. "What makes you think that Valentine's
change of plans had anything to do with your brother?"
"Because," Clary said with grim certainty, "only Jace can
piss someone off that much.

Author: Cassandra Clare