Harry wasn't sure what time it was, but he'd spent some time now clinging to a tree for dear life in the darkness. Somehow he'd managed to hang on to his wand, but just barely, and for this he was thankful because he had something to light up the night and keep him company. He'd weakly climbed higher and higher up the tree as the water had continued to rise, not certain if he was at the edge of the Forbidden Forest or not. In the distance he could see the castle lights in the tallest towers and could tell the lower floors had been flooded because the lights were out, but this was all. Even the stars were blotted out by clouds and it left Harry feeling lost and alone.

Once Harry thought he'd heard a cat in the distance trying to swim to safety, but it had begun to rain only moments after and the noise was gone.

When Harry was at the top of the tree, he had a hard decision to make. He knew he couldn't stay with the tree forever because eventually it would be completely covered, but he was also too weak to swim very far and couldn't see anything to use to float on. He didn't know of any transfiguration spells that would help him either.

At the last moment, Harry abandoned his tree and rolled onto his back, deciding he would try to float and just use his legs to conserve energy but the waters were swift and violent and he ended up under the water most of the time. After a long struggle, he felt very lucky to find another tree that was just a little taller and not as far underwater yet. If he had to guess, he would have said it was past midnight now, and he wondered if Snape would tell Dumbledore he'd been swept out of the castle so that they could send some kind of rescue for him. Surely they could transfigure a boat or something?

Harry clung, soaked, to the second tree for as long as we was able before it too was under water and he began his tiring swim towards the castle again, exhausted and scared and quite sure he was going to drown before he found something else to hold on to. He thought frequently of Hagrid in his hut and wished he could keep his mind from wandering to Hagrid and what might have happened to him if he had been caught unawares of this freak flood. He also wondered how many bodies were in the water with him, or if he'd come across the giant squid or some merpeople or other dangerous water creatures from the lake.

In the darkness, Harry bumped into something hard in the water and panicked, sinking for a moment before coming back up frantically. He didn't know if it was a body or a piece of wood or something else and his mind wasn't clear enough to cast a lumos again to see. Harry went under again and just when he thought he wouldn't make it back to the dark surface, something grabbed him and pulled him onto a hard surface.

Sputtering, Harry gasped for air and opened his eyes, jerking violently to see where he was and what kind of danger he was in. The thought that this was all Voldemort's doing had passed through his mind frequently as well.

"Calm yourself Potter," the relieved voice cut through the darkness and a light suddenly shined into Harry's eyes, causing him to squint to see the dark form that had rescued him from certain death.

"P- p- professor?"

Harry wiped the water from his eyes and his rescuer lowered his wand. "Yes Potter."

Without warning Harry fell backwards into the rowboat laughing, not caring that he'd just knocked his head on the wooden bench behind him, and Snape glared down at him with concern then.

"I do not find this amusing Potter."

"Oh my gosh, I can't breath," Harry said, holding his side.

Snape knelt beside him then and checked his pulse as Harry continued to wheeze, trying to get air in.

"You were under the water for too long. I believe your body is having trouble taking in air."

"What- what do I do?"

"Relax. There may be water in your lungs." Harry lay there trying not to panic as Snape waved his wand over Harry in the rocking boat and said several spells before Harry felt like a weight had lifted off of his chest and he was able to breath freely again.

"You can breath now?"

"Yes."

Harry tried to push himself up to a sitting position, but now that he was in a boat he felt too exhausted to do it.

"I didn't think anyone would come," Harry said weakly.

Snape glared over at him as he stuck his hand into the water on one side of the boat and began to paddle slowly towards the castle.

"Why would you assume such an idiotic thing? Half of Slytherin saw you go."

Harry turned red. He didn't think it was idiotic. His friends didn't know where he was, and no one else had ever cared enough to try to rescue him from any kind of disaster. Only Ron and his brothers had ever tried to save him from the Dursleys... why was a flood any different? Either way he was in danger of dying.

"What, what are you doing?" Harry pointed to Snape's arm in the water.

"Getting us back to the castle, what does it look like I'm doing?" he snapped.

"Why don't you have paddles?" Harry asked. Snape knew transfiguration, he figured he would have transformed something into paddles.

With another heavy glare, Snape said, "I dove out into the water after you and found myself outside the castle with no means to get back in. I eventually happened upon one of the school boats, without paddles. I have nothing to transform into paddles either."

Harry felt stunned. Snape had gone out into the water after him? "Why would you do that?"

"Do what Potter?" He was in a foul mood and felt thoroughly exasperated with the teenager in the five minutes since he'd found him.

"Nevermind," Harry mumbled.

"We would get back to the castle sooner if you helped," Snape said, feeling more and more grouchy as the night wore on.

Harry tried to sit up and fell back to the floor twice before he managed to get up and to the opposite side of the boat where he stuck his arm in the water and then promptly toppled in. It was a moment before Snape's hand shot down into the depths and hauled Harry back into the boat again, sputtering and startled. Unbidden tears sprang to Harry's eyes from the fright and he felt like a fool for being a fifteen year old and crying in front of his hated professor.

Snape seemed to be just as startled at Harry falling in without any attempt at stopping himself, and at the sudden tears the boy was furiously trying to wipe away.

"I will continue to paddle. You lie down."

Harry did as he was told and turned on his side so he could hide his face from this man that hated him, and had for some reason risked his life to save him. It didn't make any sense, and in his tired and weakened state, Harry fell into a fitful sleep in the rocking boat, the flood following him into his dreams.

* * *

Harry woke as the sun came up, and didn't feel as though he'd slept at all. Groggy and trying to sit up in the rocking boat, Harry was surprised to find Snape still there at the other end, paddling and looking tired. They were still a ways off from the castle, which was now surrounded by very deep water. Harry could see Gryffindor tower and several other towers sticking up, and just a tiny part of the lower castle.

"Potter," Snape acknowledged him dryly when Harry sat up and then fell again when a wave hit the boat.

"This is crazy," Harry said quietly and in awe. "What happened?"

"I do not know."

"It's all just... gone." At least he knew his friends were safe in Gryffindor tower, unless the water rose anymore. The Professors should be able to transfigure boats for everyone though if it came to it, he thought. Hopefully with paddles.

Harry moved to sit again so he could row, but Snape said sternly, "Don't."

"Sir?"

"I don't feel like pulling you out of the water again."

"Oh."

Harry's stomach grumbled loudly as they grew ever closer to the castle, and he let his eyes scan the water, hoping that if there was anyone still alive out there that they'd be able to help them, but he saw no one, not even the lost cat he'd heard the night before.

Eventually the boat bumped into the stone wall of the castle and Snape looked up the wall critically, wondering how they were going to reach the window that was twenty feet above them. If someone had seen them coming, they would have been there by now with some sort of ladder or rope.

"Think we can climb it?" Harry asked, looking up at the window as well as the light grew brighter over the horizon.

"I can," Snape said critically, staring at him and wondering why he was so weak. Snape had been treading water for half the night as well, but didn't find himself falling overboard. There was obviously something wrong with the boy.

"Maybe there's a window lower down somewhere," Harry suggested then, feeling too tired to care that he was there with Snape, or wonder why the man wasn't being foul to him this bright and cheery morning.

"Perhaps," Snape said, and began to paddle them off around the castle.

As they moved slowly around the castle, Harry using his arm to push them off the wall when they got too close to it, he wondered why there were no students or staff up on the roof searching for survivors in the waters outside, and grew worried that somehow no one inside had survived.

"Do you think everyone made it?" Harry asked, the sound of the boat hitting the castle every now and again the only thing really keeping him awake.

"I do not know. All of Slytherin was accounted for after you brought Draco out of the Dungeons. Most of Hufflepuff were already up on the second floor when I came down from the staff lounge."

"Good," Harry said. He really didn't want to find any bodies floating in the water. After an hour of agonizingly slow progress, they finally found a window that was just under the water.

"There haven't been any others," Harry observed when they stopped to look at the window. It was obvious that whatever room was beyond it was flooded as well.

"It is unsafe," Snape finally concluded after long moments in thought.

"But we'll be exposed out here," Harry said. He knew from experience how unpleasant sunburn could be, and drinking the tainted water all around them wouldn't be good either.

"We will find another way."

"And if we don't?"

"If I take you in there you'll drown. You can barely sit up." Harry could tell the man was beyond tired himself, tired enough not to put Harry down or insult him or berate him for arguing with him.

"We'll get sunburned, we'll be cold from the wind, and we'll have no food or clean water."

"You will survive Potter," Snape said bitterly and with a glare.

Harry's stomach grumbled again. He hated to pass up the opportunity to eat if there was one. He'd only been allowed one meal a day with the Dursleys, sometimes none at all, and he'd slowly been working his way back up to three meals a day in the month since they'd been back at school. Yesterday was going to be the first day he was going to have three, but then he'd had to skip dinner for detention. After long moments of consideration, Harry finally said quietly, "I need food." He hated to admit that he was going to pass out soon if he didn't get something in his stomach. He was already feeling weak, and was just adding dizzy to the list of things threatening to overtake him now. Snape seemed to realize that it was a lot for Harry to admit as well.

"The last time you ate was?"

Harry looked away out into the watery landscape. "Lunch yesterday."

"Is that why you are so weak?"

Head snapping back to Snape, Harry was suddenly angry and snapped, "Maybe I'm so weak because I had to skip dinner for your detention, then I had to swim Malfoy out on a table because he didn't know how to swim, then I spent all night clinging to a tree and trying to swim back to the castle."

"Agitated are we?"

Harry hated the little smile that had come over the man's lips now. Without warning he climbed out of the boat and used his wand to vanish the stained glass window just under the water.

"Potter! Get back in the boat!"

Harry didn't even bother glaring up at the man. Determined not to be seen as weak and helpless, and determined to get food and escape the nosy bat in the boat, Harry held his breath and went under and through the window.

Once inside Harry realized just what a mistake he'd made, because the room was filled with debris. It was obviously someone's office. There was a broken table and chairs, books, quills, ink bottles, and a number of other things. Fighting his way through the junk, Harry hoped he'd be able to get the door open on the other side of the room and somehow find a pocket of air.

Feeling that he was finally out of air and unable to hold his breath any longer, he struggled to get the door open and failed. He felt movement behind him then and Snape appeared, wrenching the door open with nothing short of pure willpower, and dragged Harry through to the other side where there was a higher ceiling and they were able to surface for air.

"You're an imbecile," Snape spat at him as he gasped for breath in the one foot space between the water and the ceiling.

Harry felt unable to say anything and allowed Snape to drag him to a desk that was still in tact where they were able to stand instead of treading water.

"Now I must take you back through the room and out to the boat you little fool."

Harry stared at him and after he finally caught his breath he said, "No, keep going. Maybe we can get more space in the next room."

"More space? Potter the whole floor is under water!"

"I think that was Professor Flitwick's office," Harry said of the room they'd just come through. "I think this is the Charm's room. On the other side should be the auditorium."

Glaring at him, Snape looked around and tried to gain his bearings. If Potter was right, the Charms auditorium would have more room because it had a higher ceiling and also a raised platform where Filius liked to stand and teach. There was the remote possibility that they could sit on a table high up and be dry.

"You stay Potter. If I find you've moved one inch, I'll-"

"Drown me?" Harry supplied, but his Professor only glared. The man took a deep breath and then disappeared under the water for what Harry felt were long minutes. He began to worry and wonder if the man had drowned, and just when he considered going under to look for him, Snape surfaced again.

"The Charms auditorium is on the other side. You will follow me through and hold on to the back of my robes."

Harry steeled himself for another perilous underwater swim, and they both went under.