Enjolras, Combeferre, Jehan, and Grantaire have a group chat called Insomnia Anonymous so they can talk to each other when they can't sleep (the name doesn't make sense but R named it when he was drunk and hadn't slept for 52 hours and everyone just let it happen). Jehan posts poetry on there and they are kind of nonsense sometimes but each of them gets a kind of warm feeling in his chest when he reads one of J's insomnia poems, like their mother is singing them a lullaby. Enjolras actually gets emotional after like 65 hours no sleep and he sends long rambling paragraphs about how much he wants to help the people and how much he cares and how angry he is at the bourgeois and does that make him a bad person because he hates as deeply as he loves? If R is really out of it he will send whatever terrible self-loathing thoughts are floating through his head at the moment. Sometimes that merits Jehan coming over in the middle of the night with a pastry or two. When Combeferre really shuts down he gets very philosophical and existential and all of those ideas mix with his scientific ones in these long ponderings on the stars and humanity and the color of Courfeyrac's eyes. None of them mention this chat outside of it. None of them really respond to the others' texts. They just write their own and understand that the others are listening in the same way that they are, but knowing that responding would make it fake or forced somehow. Because honestly they're too dead for conversation. They just need the presence of each other.
