Remus didn't quite process Sirius' death for a very long time. When he first got back to Grimmauld place it was silent, and he sat staring at the wall. When he reflected on it, he felt as though he lay there for eternity, barely moving, staring at a wall.
When it did hit him, it was full force and heartbreaking. When he reflected on it, he was lost for words trying to describe the feeling of absolute desolation. The rapid, devastating realisation that he would never see Sirius again. That he didn't even have a grave to mourn, or that many fond memories to look back on.
The sobs that wracked his body went on until he was too exhausted to continue. He fell asleep with the image of Sirius' laughing eyes burned into his brain and Sirius' bright smile etched into his heart.
By the time he woke, he was crying again. In his dream he'd been with Sirius, laughing and joking. It hurt his heart to see his face in the smog that occupied his mind. There, but not there, was how he would later recall it. They were together, but Remus was alone.
Over the next few days a total of four people visited Remus in his increasingly grim room. Molly came almost daily, with food and tea and things that Remus no longer cared about. Next came Albus, the most surprising of all, stating in his calmly infuriating way that Remus should perhaps visit Harry and share in his grief. Remus replied with a glare and a hex on his tongue that he could not come to regret. Third came Moody, some time later, to growl at him and pat him on the back then abruptly leave.
Last was Tonks, who sat staring at him in the chair by the bed. When he cried she patted him on the back and whispered soothing words to him. When he stared she stared back, smiling and talking about anything else. When he turned away, she dragged her chair over to the other side and encouraged him to eat the cooling broth that had been set by his bed. When Remus reflected on it, he realised she must have been going through her own grief, her own pain.
When Remus reflected on it, it was simply too late.
He saw the green light coming towards him, a second too late to dodge, with barely enough time to reflect on this, and so much more, before he slumped to the ground. For a few brief seconds, he was stuck between the people he had loved and the people he did love, past mixing with an even further past.
When Remus died, he was still reflecting of Sirius' laughing eyes and bright smile. When Remus died, he was still reflecting on Tonks working through her own grief to reach out to him.
AN: I'm sorry this took so long to get going, but I have some free time right now! If you want to send me a suggestion for a story or even a universe in which to write one (I'll try my best..) I'd love that! :*