“I can go no further,” Guthbrandr announced. “Ahead you will find… me, for lack of a better term. Take care that you, yourselves, do not become infected by its poison: I think even your Valkyrie’s feather would fail to keep you sane then. And know that I lay no more claim to anything in there which has survived these centuries.”

“You have our thanks.” Einarr inclined his head to the gruff old man.

He chuckled darkly. “I should be thanking you, I think. If you think I’ve made your journey easier…”

“I think you’ve made our continued journey possible, at this point. Which is a fair sight better than driving ourselves mad with endless sailing.”

The old man shook his head, still chuckling. “Well - never mind. If you win, you’ll not see me again, so this is farewell.”

With that, the shade that was all that remained of Guthbrandr Eyvindersen strolled nonchalantly back toward the mouth of the cave and faded from view. As he went, Arkja’s eyes suddenly went wide. “Well I’ll be.”

Einarr peered ahead, searching for some sign of what they were after. “You still didn’t think he existed? Your story is what put us on the right track in the first place.”

“It was a campfire story…”

Einarr started forward, Jorir and Erik close behind.

“You’d be surprised,” Runa said, falling in behind them. “How many of those have their roots in history. Especially the ones that stick around.”

“Keep your wits about you,” Einarr ordered. “We don’t actually know what we’re facing here, other than some sort of corruption.” And gods only knew what more contamination might do to him, Erik, or Irding.

***

The river cave twisted on for some distance further, until the daylight from outside was well and truly gone. Strangely, they did not need to strike a torch: some sort of dull, greyish ambient light suffused the cave.

Einarr stopped short when he saw ahead of him what appeared to be a keyhole set in an otherwise blank section of the cave wall. Ahead, the ceiling sloped sharply downwards, until it nearly touched the water’s surface. His brow knit for a moment in consternation and he opened his mouth to ask why, but then cut himself off with a sigh.

“I want to say that this is one of the strangest things I’ve ever seen, but after this last season it’s nowhere close.”

Erik barked a laugh. “Ain’t that the truth. Nothin’ for it but to see what’s on the other side, though.”

He could hear Arkja muttering about what he’d signed himself up for even as Irding urged him on. With a sympathetic half-smile, Einarr lifted the key on its chain from around his neck. Based on all the information he had, there really was nothing else to be done.

Einarr slipped the golden key into its lock. It turned smoothly, and with a click a seam opened in the rock wall.

As they watched, the vertical line of the seam spread outwards in both directions until it formed the outline of a door. With another click, followed by the grinding of stone against stone, the door opened inward.

The space beyond the door was blacker than night at first, but in the span of time it took Einarr to blink an eldritch purple light popped into existence. Surprised, Einarr glanced back at his companions. A shout of alarm escaped his lips.

He could see skin - faintly, and tinted blue-purple like the light led him to expect, but the whites of their eyes and where they showed teeth glowed like stars.

The others (they were actually still his companions, right?) likewise recoiled in surprise and horror. Arkja hopped all the way across the width of the cave, his scramasax leaping into his hands. “Back, demons!”

“Look who’s talking,” Irding shouted, moving between the frightened local and Einarr, his own axe free of its belt loop. Even Einarr had drawn steel in that first moment of shock.

“Everybody, calm down!” It was Jorir who took charge in that moment. “Nothing we were told suggests we’re up against a puppetting beast, so let’s not let it in our heads at the drop of a hat.”

Einarr cleared his throat, suddenly very glad his man at arms was a sensible sort. “Jorir’s right. If we turn on each other right away, we’ll never be free - none of us.”

Now that the initial shock was past, it was true he could feel a pulsing ill will, a concentrated source of evil - but it was through the door which had just opened. “The thing we need to defeat is in there.”

Irding stared into the darkened, oddly glowing chamber for a long moment. “But, there’s nothing there. Nothing to fight, anyway.”

“No,” Einarr mused. “No, there wouldn’t be. The old man said this is where he was, and that really all that remained of who he was - was a shade of his will, and the accumulated, corrupted magical power he had taken into himself.”

Runa’s face, ghoulish in the light, nodded encouragingly.

“That means, if my guess is right, we have to some how disperse that,” he pointed with Sinmora’s bare blade. “Without getting any on us. The Matrons may have quelled the black blood’s influence, but we know we’re not fully purified. And I would never forgive myself if we made it this far only to fall to a ball of light.”

The thing he had pointed at, the aforementioned ball of light, looked like nothing so much as a cloud swirling in the middle of the chamber, roughly round but churning as though it were a storm in and of itself, black and glowing violet and reaching.

Arkja, who had edged closer to get a better look at the thing which set all their hearts to pounding, asked the relevant question. “How?”

Einarr set his mouth in a grim line. “If I knew the answer to that, we’d already be doing it.”