After returning to the Institute Jace couldn't sleep. He woke, screaming and shivering with the memories of his supposed father's twisted lessons, the icy cold of death clawing at his soul, the feeling of his blade sinking into his grandmother's body. He woke, and he was alone, because Clary was another person he'd failed.
Breath coming in gasps, Jace dug the balls of his hands into his eyes, trying to banish images that haunted him even after waking. So lost was he in his nightmares, he almost pulled the knife from under his pillow when a hand came to rest on his shoulders. However, even through his terror, the part of him that hadn't been entirely his own for almost 10 years recognized the calloused fingers, the familiar presence of the one person he never had to hide from.
"Alec..." Swallowing a sob, Jace threw his arms around his parabatai's shoulders and buried his face against the rune-covered neck. Alec's embrace was warmth and safety and the only thing that could make the shadows melt away, just as they had when he'd come for Jace in Lilith's mind prison.
His fingers carding gently through Jace's hair sent shivers of a much more pleasant nature down Jace's spine, as did the soft hum of his voice in Jace's ear: "You're alright, you're alright. I'm here, and I'll never let you go again."
Jace clung to him, his breath slowly returning to normal, until there was an unmistakable press of lips against Jace's temple. Immediately they both froze, a jolt of recognition reverberating through the bond that connected their very souls. Slowly, Jace lifted his head and met Alec's wide eyes, their heartbeats speeding up simultaneously into an exhilarated gallop.
When they kissed, Jace knew he'd never have to sleep alone again.