Clary has never been any good at putting things back together. When they were in middle school and she accidentally knocked over Simon’s Lego Millennium Falcon, he’d already known to say it was fine repeatedly and usher her out the door instead of accepting her offer to help him rebuild it; if he’d let her try, the wings would have ended up upside down and there suddenly wouldn't have been space for the engine. Her heart is in the right place, usually, but it doesn't often translate to her hands. So when he hears through the shadow world gossip mill that Alec's parabatai rune disappeared briefly, it doesn't take more than one look at Jace’s face to know that she’s been fucking around with the threads of fate again. And, well. She's never been that great at sewing, either.