The fourth time Severus tried to keep it together:
It was damned freezing. Severus could only hope Potter wasn't going to die of frostbite before ever finishing Albus' task and actually meeting his fate. If Granger wasn't clever enough to cast a good warming charm, he'd personally throttle her in the case of Potter dying from pneumonia after where he'd put the damn sword. An act of bravery? How was dragging a sword from the bottom of a frozen pond an act of bravery? Not that 'Potter being foolish and reckless' hadn't become synonymous with the word these past few years, it still seemed iffy. He was going to use Albus' portrait for kindling if this didn't work.
Severus ducked further into the shadows of the trees as Potter followed the trail of his doe into the clearing. In the six months since he'd last seen the young man, he'd almost convinced himself that he wasn't still infatuated with his dead best friend's son. Now, seeing the frayed visage of the Gryffindor, he knew that that was unequivocally not true. A horrible fact, all things considered. Heart-wrenching, and for a long moment, as he watched the shorter wizard study the glinting metal beneath the ice, he had to fight with himself not to take him as far away as he could, away from this madness and the fate that awaited them both.
Severus had no illusions anymore. Neither of them would survive. No chance for either of them to do more than their duty to end the war, and certainly no chance for those grave, haunted green eyes to look at him with anything less than pure loathing. Whilst never having been much of an optimist, the Potions Master knew that one of his greatest internal failings was clinging to hope. It was what had driven him to Albus, it was what had let him speak to Lily that first time… and it was what made his eyes burn as he looked upon a young man he would never be allowed to touch or hold, never mind whatever his dreams may conjure.
Potter cast a cutting hex on the ice. He still hadn't really mastered silent casting, it seemed, and his lilting, matured voice carried on the gentle, frigid breeze blowing through the clearing. He cast again, a summoning charm, and Severus didn't blame him for the effort, or the scowl of irritation when the sword remained unmoved.
"Dream on…" Potter muttered in distaste. He dragged his shirt over his head and continued with an annoyed, bitter grunt. "Everybody's got their dues in life."
Severus ducked further behind the tree as his chest seized with the laughter he barely stopped from escaping. It wasn't funny. It wasn't. Or, it shouldn't be, not with how true it was, but Merlin. The brat really was one of a kind, and Severus could swear Lily had to be whispering in his ear. There was no other explanation for how he'd managed to continuously quote almost every song she'd ever played on endless repeat when they were teens tucked away in her bedroom.
A splash resounded from the clearing behind him, and Severus looked around to see Weasley, returned from his pity party, approaching the clearing from the direction Potter had come. Gratefully, Severus apparated before he could lose his composure further. He landed in the Forbidden Forest just shy of the wards and collapsed against the nearest tree as his shoulders shook and he struggled to get air. Apparating when he already wasn't breathing probably wasn't the smartest move he'd ever made. Death: the brat was definitely going to be the death of him.