Very obscure idea I had, so bear with me. It will take some time to develop, to please stick with it. I'll do my best to update regularly.
The longboats glided near-silently through the dark waters, the only sound giving away their positions was the rhythmic sploosh of their oars. The men standing watch along their sides stood motionless like living statues, the slight breeze created by their movement making their beards sway. The moon hung high over their heads, casting a soft, white light on their faces. The man standing forward-port side shifted and began walking silently to the bow, where he placed his right hand on the shoulder of the man stationed there.
"Kargerek," he whispered, his eyes drinking in the sight before them, "what news have you of our bearing?" Kargerek shifted and looked at the other man. Both were tall and muscular. They also looked similar, if you could look past the large, obscuring beards they wore. Kargerek stood a few inches taller than the other man, and had a few pounds on him as well.
"Quite well, Kerrek," he smiled. "It's near impossible to keep a straight course out here, but the rowers are stroking quite evenly on both sides." Kerrek nodded his approval.
"We've a big day tomorrow, brother. Why not go get rest? I've only recently woken. I can watch both sides of the ship." Kargerek rubbed his pale blue eyes and blinked a few times before stroking his bright, firey red beard as if in thought. He looked at his brother, as if sizing him up. He had almost always thought that Kerrek had been adopted. Both his parents had bright red hair while Kerrek's was a dark chestnut and his eyes, unlike his own, were nearly black. Though he knew this notion wasn't true. He remembered when his brother was born, and unless it was a cruel trick played on his family by Loki and two children had been switched, there was no denying the blood between them. He smiled again, looking into his brother's eyes.
"Yes. I think I shall. The village will be happy to see us return after such a great plunder. Father will be pleased with the gifts we bear to him." He looked over the starboard side of the longboat, watching at the small swirls the oars caused every time they dipped into the ink-like water. "On the morrow, brother."
"On the morrow," Kerrek replied, looking back out to sea. With that, Kargerek turned and moved swiftly to the sleeping compartments and lay in his hammock, his thoughts swiftly carrying him into the dream realm. Kerrek continued to keep an eye on the ocean, its waters eerily calm this far out from shore. Off in the distance ahead, he could see a low, thick fog roiling in the moonlight. It was not much cause for concern, seeing as how they wouldn't reach landfall until the following evening and there wouldn't be any obstacles between them and the shore. The night passed with no other noise than those of the oars and the waxed hull gliding through the water.
The next morning, Kargerek woke quickly, as if jolted from his rest. All was as it had been when he had slept except for the small amount of light that was now shining through a few slats of wood that served has his makeshift window. He roused himself swiftly and headed for the deck, placing his helmet onto his head and re-strapping his ax to his back. As he exited the stairway onto the main deck, he was greeted with a gray blindness. The fog that they had run into the night before now surrounded him to a near-sightless state and it was nigh on impossible for him to see his hand before his face.
"Kerrek," he called, his voiced dulled by the fog. After a moment, the response came, hesitant but loud.
"At the stern, Karg," he replied, thumping his foot against the hard wood to give a location. Kargerek stumbled back to the rear of the boat until a large, burly figure slowly manifested in the gloom.
"What has happened," Kargerek queried, his eyes fighting to keep the silhouette of his brother in sight. His right hand grasped the railing as he guided himself back to his kin and stood directly next to him.
"We happened upon the fog last night," he stated, his eyes still stuck on their destination. "It was light enough at first, you know, the usual amount of fog," he said, waving his had dismissively around his head, "but then its thickness increased." He sighed heavily, finally moving his eyes for the first time in several hours. "Its almost impossible to keep our bearing."
Kargerek placed a comforting hand on his brother's shoulder, nodding. "
"I understand. Do your best, and we'll make it home." He cast his gaze around the deck, searching for any sign of another shadow and straining his ears for any sound of another soul on board. After a moment, he looked back to Kerrek.
"And where are the rest of the men? They should be up here working by now." Kerrek nodded a reply.
"I told them to stay below deck. If one of them fell overboard, we'd never find him again. Odin knows we need every man available when we return," he said matter-of-factly. Kargerek agreed and nodded. "A wise choice." The stood in silence for several moment, Kerrek attempting to keep the ship on course while Kargerek merely stood as support. It was he who broke the silence.
"When should we be hitting shore if all goes according to plan?"
"By nightfall," Kerrek said. "Because of the fog, the sun couldn't wake you at your normal time. I'd suspect we're already around noon-"
His estimation was cut short when out of the gloom came a loud, rhythmic pounding. The two brothers looked at each other at the same moment, their eyes wide with fear.
"War drums," Kerrek whispered.
"And the warriors are with us," Kargerek groaned. Without missing a beat, he headed back down towards the staircase, pounding his boots on deck as he did.
"Rise, men, and grab your blades! The southern tribes must be attacking! Hear the Drum! Hear the war calls! Let us fight for our village and meet them in battle to defend our people!" Men began pouring out of the hold, their axes and swords, spears and shields in hand. "Odin be on our side today, and may Thor lend us his strength! May we all survive this attack, but for those who will not, may the Valkyries carry them swiftly to Valhalla, for now we join the fray! For the Gods!" Their cries of 'For the Gods!', 'Praise to the All-father!' and 'Thor's Strength' ripped apart the air, and the distant war drums faltered for a second, but they quickly settled themselves and proceeded to go faster. Kerrek looked over the men on deck who were waiting until they could jump into the freezing water below only begin slaughtering their enemies.
"This will be a day to remember," he said to no one but himself as he reached for his double-bladed war ax and bared his teeth in a sour grimace, the anxiety of the upcoming battle beginning to wear away at him.