The letter doesn’t say much. Only informs her to look out for the wellbeing of her friends. Newt falls suddenly ill with no cause or cure that afternoon. An owl brings her a letter as she sits vigil by his bedside.
Here is your first and only warning of the perils of disobedience. Go to this address. Leave no one alive. No one can know it was you. Do not fail, or your friend will die in agony.
What else can third-year Leta, so used to cruelty and mistrust from all around her, do but obey?
According to the file, the flat should contain only a portly man, self absorbed and forgetful. Leta floos out with the powder given and walks to the flat. She is unable to use magic, but being locked out enough makes her able to quietly scale the walls and jimmy open a window to small for anyone but a child. Leta lands in the bathroom and curls up quiet and still just like her nanny taught her when her father truly raged, snug as a bug in a rug and just as sneaky. Eventually she uncurls. He will be back from his job, soon enough. And she must be ready. Her eyes skitter over his straight razor but- no. She cannot do that. She will not slit throat like some common Muggle killer. She may not be liked, but she is from two long and respected lines of pureblood nobility, and no one, her father, the letter-writer, or even herself will take anything away from that.
The razor is left behind as Leta walks into the man’s flat proper. It is proper and stingy, the only frivolity a white baby grand piano fit into a corner with extension charms. The sleek piano stands out against the mundanity of the apartment, but even being near the piano makes fingers ache bone deep as the memory of another scale, another arpeggio reverberate through them. From impulse, Leta cuts a string out of the piano, a coil of wire that looks sharp and deadly. She practices on the fruit and flowers in the centerpiece until she knows the pressure that will make the wire bite through cleanly and without hesitation. She chews on a slice of apple until she hears the pop of Apparition and then she slides into a corner on cat-quick feet, breathes and is not seen not heard good quiet demure obedient small-
(Leta’s wandless Disillusionment had been perfect from the age of four. The consequences would have been too dire, otherwise.)
The man (there was no name in the file) eats dinner and brews himself tea, which he takes over to the piano as he starts to play, scales and arpeggios, as Leta breathes and thinks of Newt feverish and dying up in Scotland. What is this man to her? Nothing. She would never meet him or care for him. She would rather kill him than have to meet Newt’s family and go through five joyless years of Hogwarts alone and hated. This man was not worth Newt’s death.
It is the work of a few blissful moments, then, when a note is not played, to step forward as the man leans over to check the strings and just- pull firmly and cleanly. Just like slicing an apple. Easier perhaps, being still heard and not seen, cutting through and to the side until the man’s eyes were meeting hers. She leaves the wire, ends still sticky with apple juice, inside the gaping neck wound for the letter-writer or the Aurors to find first as she glides out of the room. She floos back to Hogsmeade and sneaks into Hogwarts, blood simply new freckles on her face, lace gloves discarded in the Great Lake.
The Prophet notes the murder as Newt recovers over the weekend. Leta sits with the the paper in her lap, reading about the professionally cleaned scene- no evidence. Under the paper rests a note from the letter-writer, now a benefactor of sorts, who spirited away any evidence and congratulated her on her creativity. There was a book list, with titles that no law abiding witch or wizard should read. She planned to start with How to Aggravate Aurors: The Criminal’s Guide to Staying Out of Azkaban. After all, thinks Leta, flicking her newly acquired straight razor in and out of its handle almost without thought, I’ll be called upon soon.
“-and of course, dear associate, now that you have proven yourself obedient and reliable, I will contact you again soon with more mutually profitable business. I hope you have only the best of luck until then.