She felt the heat to her right, still distant but already clearly growing, in both intensity and in proximity. She felt tears leaking out from under her closed eyelids. But more than anything, she felt a remarkable warmth against her chest, just under the notch in her collarbone. The kyber crystal that her mother had given her, so long ago it seemed. There was a sound, now, a sound that quickly became a physical thing, a sound like every storm on every planet all raging at the same time. The sound traveled with the heat, which had already become nearly unbearable, driving sweat down her face to mingle with her tears.
Jyn slipped an arm from around Cassian's back, trying to bring her fingertips to the kyber. She could still feel the crystal's warmth over the rising, unimaginable heat, and it was a comfort such as she had never known.
The light was so bright her eyes, shuttered though they were, went blind. Her skin began to blister. There was no sound, no sound at all, for her eardrums popped and split. Somehow, a part of her brain recognized a tremendous shift in air pressure, and her spine crackled, her organs cramped, an ancient alarm system shouting despite it all for her to run. But Jyn smiled. The kyber radiated, it glowed; it wrapped her up in a balm, and it suffused her with love.
"Papa," she whispered as she died.