There was a pause in the air as the auror made the usual noises about strict confidentiality. She had, of course, heard them all before and knew that the Auror's Office was about as confidential as a pair of old socks - very holey and righteous. Let all sorts of things in and out but would proclaim to anyone watching that it couldn't possibly be the case.
"I've heard the claims about confidentiality before, I'm afraid. But while your concern for my well-being is admirable, I can take care of myself. I've no doubt you can take care of you and yours, but you have to understand how connected these people are. You may not like what you find if you dig too deeply, and you may find other people suddenly become very interested in what you know."
A deep breath. "Sometimes it's better not to know. A little plausible deniability goes a long way."
Suddenly the table between them shrank, and the auror began to... insist... on a demonstration, with a curt reminder of what was considered 'dark magic'. Fortunately for her, illusions weren't generally considered dark magic.
Oh, well, if he wanted a demonstration, who was she to refuse?
"A demonstration? OK, let me think a moment. Some of it was a bit of a blur. So the first things I did were to talk to the prisoner that was in fact innocent. He didn't take much scaring."
Deitha stared off into the middle distance, thinking, and closed her eyes, before mouthing the same incantations she'd used that day. As she opened her eyes, they had taken on the last blues of twilight before night falls, and her voice dropped an octave. "I TOLD HIM TO GAZE UPON ME, AND THEN I EXPLAINED WHAT WOULD HAPPEN IF HE DID NOT TELL ME THE TRUTH."
She coughed heavily, trying to get her voice back to its normal pitch. "It didn't take much, poor sod, he hadn't had a lot of constitution before he'd gone in. I made some noises about cursing him to stay there forever as a ghost, watching his entrails be eaten by the rats, and that he'd be stuck there with the dementors forever, without even death as a release. Spode saw all this, I assumed that was in his report."
There was a pause in the air. Clearly the important part of the story was to come, and she needed to leave Odhrán out of it as best possible.
"Then I heard a noise, several noises actually, and went to investigate. If there was going to be trouble getting off the island I wanted to know sooner rather than later. What I saw was someone there on other business casting confrigo at the dementors and they weren't exactly impressed with him. Whatever he was doing, it was keeping them at bay while he was trying to speak to one of the prisoners."
Another deep breath. "I'm sure you know that already, of course. So... the dementors were coming. I don't know if you know how a Patronus really works against the dementors, but it's not quite what people think. A Patronus is a manifestation of happiness, and dementors can't see it, only sense it. Thing about a Patronus, it's something a dementor can't feed on, there's nothing there to actually eat, only the projection of it. It'd be like you or me trying to drink a picture of a cup of tea to quench our thirst."
She could feel her fingers twitching. Her specialty wanted to burst forth, naked and unashamed. "But what if you could project something else as a projection in a similar way?"
Deitha clenched her right hand into a fist, then gently flexed her fingers in order from index to pinky and back. She had to not let this out of control.
"And so I summoned one of these. Sort of an anti-Patronus, but instead of projecting happiness, it radiates fear. Fear, the threat of its hunger. And seemingly relentless."
Trying hard to hide the shaking, she summoned a single small shadow that coalesced into the familiar form: resembling a scorpion, but with more legs, two tails each equipped with stingers, and a monstrous pair of front claws that looked capable of snapping at almost anything.
She caught the creature with a swift levitation spell to keep it in one place. "How do you like it? The dementors didn't care much for my friend here, and I summoned a couple of illusions like this, but bigger. And since it is nothing but an illusion it has no emotions on which a dementor can feed. Imagine their reaction: here is a creature they have never seen, that knows no emotion of its own save its own hunger, and radiates fear."
Deitha kept the creature spinning gently in the air for Harrison to get a good look at.