The first night of a full moon was always eventful, so were the second and third, however Harry Potter had no idea how eventful this full moon was going to be.
Since Minerva Mcgonagall had become headmaster, Harry got away with some things that probably shouldn't be allowed, but what else was new really. Harry had been able to get Remus a job at Hogwarts again, he mainly helped Hagrid, but Harry often found a way to 'need' his assistance in his 'defence against the dark arts' classes.
Remus went home every weekend to be with Sirius, but full moons meant Sirius came to Hogwarts, flying in on Buckbeak's back no less. They had decided it was safer and more comfortable for Remus to utilize the forbidden forest. Harry had learnt how to become an animagi to help his godfather and the three of them spent three nights a month running amuck in the forbidden forest, making sure Lupin didn't hurt himself or anyone else.
After months of dancing around each other with long glances, late night discussions (and wine), marking papers together, trading books and ignoring that one Christmas that Peeves made them kiss under mistletoe; Harry had started seeing Severus Snape romantically (much to Remus and Sirius' surprise and slight distaste). Harry asked for the potion's master to work on a new potion for Remus, to help with the transformations. Lupin wasn't a spring chicken anymore and it took more of a toll on his body each time the werewolf took over.
It had taken three long months and a lot of late nights doing research, but Severus finally thought he had a potion brewed that may work, but he was still not confident. According to Severus, the potion would strengthen the human body while weakening the werewolf, if it was taken an hour before moonrise. That was the theory anyway, the only way to truly test it's capability was for Remus to take the potion.
The next full moon came and it was time to try out Snape's potion. The four of them trekked out to the darker depths of the forbidden forest. Once there Lupin drank the potion and then they waited for moonrise. It took longer for the moon to reach that part of the forest, it was one of the reasons they chose that spot.
Sirius and Harry waited until the time was close and then they turned into their animagi and sat by their partners, who stroked their fur as they continued to wait. It wasn't long until Lupin began to pant, the other three were immediately alert, Severus illuminated the tip of his wand in time to watch his old school fellow turn into a growling beast.
Once the transformation was complete and without warning, Lupin turned and took off running, leaving the others to chase after him. Severus cursed aloud, this was not the outcome he was after; it appeared that in making the human body stronger, the potion had also strengthened the beast inside. There was no time to reverse it now though, all they could do was follow and try to keep Remus out of trouble for the rest of the night.
Unfortunately, trouble presented itself in no time. Remus had run into a small clearing, which was unusual to find this deep in the forbidden forest, and it was not empty; on the far side was a glittering, golden light hovering between two ginormous trees. The werewolf paused for a moment and sniffed the air before howling. The others stopped a few feet behind, waiting to see what he would do and trying to avoid scaring him away.
Lupin growled and then charged at the light, it was too late by the time the others could react, the werewolf was gone, all they could do was follow him into the unknown, and without hesitation they did.
Sirius came through first, he was blinded by the sudden sunshine but he followed the scent of his lover and Harry followed him with Severus coming through last, he was probably the most aware of the shift of time and place. They were still in a forest but it was certainly not on the Hogwarts' grounds or possibly even in the same country.
Severus caught a glimpse of two men standing nearby, when one of them yelled something at him, he pointed his wand at them but decided they weren't a threat; it was more of a concern to catch the werewolf and so he kept after his fellows.
The potion's master was barely out of eyeshot when he heard a loud noise; he ran faster, there was nothing good about that noise. Severus reached a road just after Harry and Sirius. There on the road was a muggle car with the front dented inward and two startled young men stared out of the windscreen. On the ground in front of the car was the werewolf, Lupin.
Harry and Sirius transformed back into their human forms at the edge of the forest and ran over to the motionless body, praying that he wasn't dead. The beast shrank as they moved and returned to a naked, but still breathing, unconscious man.