Which they are. Sadde's suggestion that they try focusing on shorter parts of memories for a higher happiness-per-second value helps him but not Miranda, so he ends up with a more solid fog. Still just fog, though. They continue reading books about it, and it seems to just be that idiosyncratic. Interestingly enough, some books written by alchemists also have mentions of Dementors, trying to figure out what their symbolic value is and whether it's possible to integrate it. More advanced books are in the Restricted Section, and they won't have access to it until at least Professor Slughorn gives them the go ahead.
The year passes. Willow is consistently good at the theoretical parts of classes and consistently bad at the practical ones, mostly due to being flustered by failures and not quite being able to get over that fact. Sadde and Miranda are exceptional at Potions, and the only reason Sadde isn't also exceptional at Transfiguration is that he doesn't quite care enough about homework when all that's on the line are his grades. That, plus all the time he spends between reading about Dementors, reading about Alchemy, and trying to undo the damage suffered by Slytherins because of the Dark Lord.
That last goal has the most tangible results, for a certain value of "tangible." Slytherin firsties are divided between liking him (Jacob and two of the girls) and grudgingly tolerating him (the other boy and girl). He has thoroughly dispelled the notion that he's "just another Slytherin" firsties from other Houses (except perhaps Gryffindor) might have, but of course that doesn't make the older years all that happy. Well, not that the older Slytherins actually care that much. But he has helped various of them with various things, mostly by acting like a somewhat willful minion, since there's not much more he can do to help older students beyond that, so he's at least on talking terms with most of them (Cole and Astoria have been quite useful there, as well).
Arens is not one of them, but by now he's mostly just ignoring Sadde and hoping he'll just go away.
Summer arrives.
They return home and spend a while with their respective families, but eventually...
Well given that Sadde is completely and thoroughly drenched now, she might as well dive in too.
Willow swims away from them a bit so she can float belly up and start splashing them with her feet. They are much better at splashing than her hands.
That means she will have a harder time seeing people sneaking up on her to splash her, a fact that Karen takes full advantage of.
Sadde decides that playing fair is for the weak and now her fingers are webbed together and she is splashing much more effectively!
...so she'll play even less fair. Say, what if her skin had a more slippery texture and her feet were shaped in a slightly more hydrodynamic fashion?
The other reason for doing this is quickly and surreptitiously reaching the other two, bursting out of the water for an extra splash, then disappearing in the depths again.
Where might she be?
"Bluegh!" She looks around for the underwater shape that is Sadde, who is swimming much too fast.
Sadde swims around the little island so that she's hidden from Miranda and quickly slips out of the water, morphing back to fully human shape and waiting for Miranda to have to breathe.