It had been odd, chasing something you couldn’t see.

It would have been impossible if not for Percy, who was both doing almost all of the work and having almost all of the fun. He’d managed to get a system that pinged the location of the Node every few minutes, and then there was apparently a whole segment of algorithm design focused on how to evolve a chasing route with imperfect information. Even Adelaide had only followed so much of the math, but he seemed very excited about it.

That led Captain Mattson to have a bit of a mixed experience. On the one hand, this process involved Percy giving the Captain new directions every five minutes, which had begun to openly annoy the Captain after about twenty minutes. On the other hand, the Captain seemed to enjoy the excuse to run the engines hot and make quick, precise turns. Adelaide wished again that she had more experience, so that she would have the context to appreciate what she was seeing.

Other than keeping an eye on that dynamic, Adelaide hadn’t had anything to do but wait. She’d alerted Alessio to the situation, assuming that he would want the chance to film whatever it was they were chasing. If it was a physical object. And not invisible. He’d been appreciative, and had set up a stabilized tripod that had the odd affect of making the camera much steadier than the deck itself.

The word had spread, and everyone had been there, waiting. Which was good, because anyone who had missed it would have been really grumpy afterwards.

They could have missed it if they hadn’t been looking closely — it never fully broke the surface. But, with everyone’s eyes looking for something, there was no mistakeng that this was definitely something.

It was had to make out the exact proportions — it was still under the surface of the water, mostly. But it was massive — nearly the length of the Foam Strider itself. It was the shape of a rounded football, and appeared, through Adelaide’s binoculars, to be covered in scales like an alligators — each individual plate had to be the size of a couch or something.

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And all of it was spinning — it was almost like a perfectly thrown football, except gigantic and moving through the water, churning the water into spray when it came closer to the surface. Adelaide wondered what kind of muscles would be required to get it spinning like that, but whatever did it, it didn’t seem like something you’d want to stop before you needed to.

Other than shouting and gasping when they first saw it, nobody said anything. Adelaide didn’t want to look away, but she thought she knew what everyone would be doing. Jim would be gripping the railing with both hands, knuckles turning white, while Trish leaned her head over the railing. Alessio would never pull his eye from the camera, and Emma would be wishing they had anything that could come close to piercing those scales.

It was a relief, in a way, that there was no question of hunting this behemoth. Even if they had something that could pierce those scales — and Adelaide struggled to imagine the rocket-powered harpoon that could do so as they spun — there would be no way to keep something that big. They’d have had more luck hollowing it out to make a new ship.

After a few minutes, it descended a bit and became impossible to make out under the waves. They could still track it from its peculiar spinning wake, but the spell was broken. For now.

Adelaide found Ray in the bridge. “I think that’s the thing we’ve been chasing.”

“Well, Professor, I can’t say I disagree with you there. Captain, you ever see something like that?”

“Not spinning like that. The spinning is going to be the problem. We’ll have a hell of a choppy time getting close. How close do we need to get?”

Adelaide looked at Percy, who was already calculating the next pathing update. “It’s probabilistic, but, given that it’s a bit underwater… pretty close? Like within 100 yards? Can you do that?”

“Can I do it? Of course! You forget you are on the Foam Strider! But it will not be a comfortable ride. Let’s hope that anyone without sea legs can grow them quickly!”

Adelaide already felt her stomach churning, before Ray added, “And that this thing doesn’t see us as a big metal snack. Or a rival. Or a mate.”

That was an image that Adelaide instantly knew would stick with her the rest of her life. However long or short that wound up being.