Less 'controlled', and more 'exceedingly rare'; it is very touchy about reproduction. For context, Kolya was the one to set the bookbuyers on finding us a copy, back when I was still in diapers, and as far as they are concerned, as no one has given up theirs for sale, we are still looking; I found my copy in Cairo after Hogwarts. (Which is why I have a habit of being noncommittal whenever anyone asks if I own it; I smuggled it, and many like it, back in under the former régime, and while I do not think anyone under Our Lord's government would take me to task for literature that was contraband then -- or for the import duties I did not pay at the time -- it is easier to be vague.) At the time, Kolya was told there are less than a dozen copies in-country -- I'd not be surprised, actually, if Lucius's library contains one of them.

I am reading through the text in advance of my appointment tomorrow morning, just to refresh my memory, but on the whole, the work is about death-magic. It postulates that a wizard with a sufficiently advanced will can set up, in advance, a death-spell that will be automatically released at the time he dies -- as a form of 'final strike', revenge against whomever has killed him. Parlington claimed to have known several warlocks who managed it, but even following his instructions most carefully, no-one has been able to achieve the same effects since. (That anyone is willing to admit.) Every hundred years or so, the idea becomes fashionable again and there is a minor rush to find the primary source, but most of the citations in the literature are not complimentary.

So either our researcher thinks he has figured out something that has eluded researchers for hundreds of years, is chasing a citation down to its component bits, or wishes to test my library before asking me for something more significant. My money is on the third.

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