Author's note: This was inspired by the cover art piece, drawn by the incredibly talented Hammy. Her tumblr is hamstr and you should go look it up because it's fabulous. The concept of literally glowing hair is an in-joke in my corner of the fandom.
Enjolras slept with a small smile on his face, limbs sprawled out and hair tumbling down around his face and shoulders. The glow that surrounded him during his waking hours had dimmed, leaving him more man than marble though in truth he was always both. He slept with the stillness of one who has learned to share a bed — Courfeyrac in particular disliked sleeping alone and regularly invaded Enjolras' bed when he could not find bedmates of the female persuasion.
Combeferre, who had come over to finish a discussion about the right to property versus the right to happiness and never quite got around to leaving, sat in a chair next to the bed with a book in his lap. On the night table the candle stub he used was flickering dangerously, nearly at the end of its life. He bent closer, peering at the small print in an effort to get as much read as possible before losing his light source. He had promised Prouvaire he would return the text the next day and, though his friend would be more than willing to let him keep it a few more days, Combeferre was a man of his word. He turned the page.
The movement created a slight breeze and the candleflame flickered wildly before going out entirely. The room was plunged into sudden darkness and Combeferre blinked rapidly as his eyes struggled to adjust to the abrupt change. There was little point in relighting the candle, burnt down as it was, and Enjolras kept his spare ones in the other room. He uncrossed his legs and stretched his neck, weighing the respective merits of digging up a new candle versus calling it a night and returning Prouvaire's book later than promised. He was not particularly weary, truth to be told, and he doubted he would find much restful sleep before having finished his reading.
Enjolras shifted in his sleep and the sound gave Combeferre an idea. He reached out, eyes adjusted enough to the dark to make out Enjolras' sleeping form, and laid a gentle hand on his friend's head. Carefully, so as not to wake Enjolras, Combeferre stroked his hair, smooth strands silky against his skin. Slowly, a dim light began to emanate from Enjolras' locks, an imitation of his usual glow that grew brighter under Combeferre's ministrations. Within a few minutes Combeferre had ample light to read by once more, a steady illumination that was far kinder on his eyes than the candle flame had been. Enjolras' smile grew though he did not wake, and Combeferre felt himself smile in return. Keeping one hand on Enjolras' hair as both a sign of affection and a means to keep his light steady, he returned to his reading.