Jacen hides his emotions in the Force

Tahiri let out a breath, then asked, “So what do you want us to do, Jacen?”
“Stop the war.” Jacen slowly drew a veneer of calm over his presence, projecting an aura of tranquillity into the Force that would prevent the others from sensing the lies he was about to tell. “In my vision, the war starts in earnest when the Chiss launch a surprise attack against the new Killik colonies.”
- Dark Nest II: The Unseen Queen