In Christchurch the leaves are falling, and the white-throated tuis chuckle in the wilting rosebushes, when the Great Auk takes flight. Winging high above New Zealand's alpine glaciers; west across Australia's native beaches; island-hopping in the Indian Ocean, as the crews of tankers and pirate ships squint heavenward; a night in Madagascar and another amid the flamingos of Lake Victoria; skirting the High Atlas to loll exhausted on the volcanic Canaries. A score of nights, all told, west and north and west again, always with the waterproofed, invisible parchment chained to its foot, until at last, summoning its final ounce of strength, the great bird bursts like revelation on a radiant, heather-ridden Highland spring.

In a regal turret of Gryffindor Tower, Minerva gently dislodges the parchment and pours a nip of Highland whiskey for the Auk. She turns the small packet over and over, thoughtful, resigned. Good or bad or merely strange, the contents can bring nothing but heartache. She pours a nip of Highland whiskey for herself and breaks the seal.

It's a long and newsy letter from an old friend, a Jill-of-all-trades who teaches flying and commentates on Quidditch in Moutohora and Woollongong. It's family news, mostly; Minerva's family, not Jill's. Howard may have to retire from his mind-numbingly dull position in the Oceania Joint Patent Authority; the self-operating vacuum cleaners (not as safe as they sound) have clobbered him one time too many. Sandy's wife Melania, who's forty-seven, has just announced a pregnancy, to the chagrin of her teenaged children; "I think they're using Muggle technology," Jill hints darkly, "Hope the Healers at St. Botolph's don't find out." Cuthbert, who graduated from the Tasmanian Academy of Magic last December, has been taken on by the Moutohora Macaws. Jill encloses a clipping from the local wizarding newspaper.

Minerva scrutinizes the animated photograph: the jolly faces of the nephews she has never met; their wives, these many years now; their almost grown-up children. She gazes into the flabby, wrinkled face of the brother-in-law of whom, even in his youth, she thought so little, and then at last into the pensive concealing face, the sad autumnal beauty, of Persephone.

Thirty-nine years and thirty-nine letters; three successive Great Auks. They were born here, near Inverness, just seventeen months apart. They passed their schooldays here, in Gryffindor Tower. They were best friends for twenty years, from the time they were toddlers in matching dresses, restraining squirming kittens on the floor of a modest Highland bothy, until they went, both of them, expert fliers that they were, as soldiers in the gruesome war against Grindelwald. They haven't spoken in forty years, but she can't forget she has a sister.

Dad was a Muggle-born wizard whose goal in life was to raise a genius. His grandparents sprang from the slums of Govan, refugees of the Highland clearances. By dint of hard travail, his grandfather rose to become a factory foreman, and his father, a butcher. Recklessly ambitious in a bloody-cuffed, working-class, Clydeside manner, Jock McGonagall refused to release his clever son from primary school to pursue his wizarding education. At thirteen the boy ran away; he commenced his Hogwarts schooling two years late. He broke every tie with the family of his birth. He never once looked back.

Mum was one of the Glasgow Macmillans, pureblood of course, but that's not the sort of pure blood that most wizards would choose to brag about. Macmillans are rigidly virtuous and wholesomely dull, and they're usually happiest when they marry each other. Certainly, marrying a mudblood McGonagall had turned out to be a mistake for Julie Macmillan. The children were her only consolation, and sometimes a poor one at that.

Impish young Alexander was a severe disappointment to John McGonagall, as he said frequently in his son's absence, and also in his presence. It was left to the daughters to carry the mantle of Dad's ambition; but Persephone, bright and rebellious, would not submit. She learned the art of self-sabotage early, failing exams and racking up detentions simply in order to make her father heel. And so it fell to Minerva, the eldest and unwilling favorite, to make the goals, to win the prizes, to get her name in the newspapers—and to sweep up the littered fragments of human relationships when she got home.

It wasn't so bad at first—for at first, you see, she had a sister. Six years together at Hogwarts, one year apart after she left school—just long enough to whet her appetite for companionship again—and then the rush of wartime missions, of hectic nights and clouded days. They were a team in the Grindelwald War, a bit of a legend, like Black and Lupin in later days; not quite as reckless, but something of a legend all the same, the flying sisters, clever, fleet, and female. She wanted nothing more than to be Persephone's partner, Dumbledore's ace lieutenant . . . until her sister dropped the bomb, as the Muggle saying goes.

In the midst of the Grindelwald War, without notice, without warning, Persephone abruptly married a dumpy New Zealander whose chief attraction, as far as Minerva could tell, was that he wished to live in New Zealand.

"Don't do it, Persephone."

"I already did."

"You don't love him."

She spread her arms. "What's love? Love is a word. What matters is intention."

"The war's almost over. You're giving up so much for so little."

"I'm getting out of Scotland."

"But Persephone, you don't need to. They won't expect us to move home again. Not at our age."

Persephone rolled her eyes. "I'm sick to death of this place. I'd move to the Moon if I could."

Instead she moved to Woollongong. Then Moutohora for a year, and finally the Christchurch garden suburbs. Persephone, a housewife. They corresponded for a while, until Persephone stopped writing back. Was she too happy to need a sister anymore? Was she so chagrined by the choice she'd made that she couldn't bear to write? Minerva stopped writing; it was the most dignified thing to do. And she set an old friend to spy on her sister. Because love matters more than dignity, at least in private.

Would it ruin her mystique at Hogwarts, if the pupils knew she had a sister?

Alexander missed the Grindelwald War, ensconced with the underage at Hogwarts for the duration. In the brave new post-war world, he proved a poor substitute for Persephone. There was no heart-to-heart conversation, no companionship of equals, no steadying influence of an alternative value system to Dad's. There was just the patient, unheeded refrain, punctuating the covered-up hearings at the Ministry and the urgent late-night Floos: "Don't play Quidditch when you've been drinking."

"I only had four or five. I think . . ."

"You don't remember how many Fire-Whiskies you had?"

He twitched his nose. "Igor cleared away some of the glasses. I slept at the pub last night—didn't quite make it home . . ."

Couldn't stand up, she thought.

Ten years of that, as she bobbed and parried the blows of the rugged post-war world and found her way back to Hogwarts. Twenty years, as her hopes of marriage and children withered on the vine. Twenty-two years. Twenty-four. What would you do? She was the one who brought him into the Order when the "First" War started, and she was, she supposes, indirectly responsible for his throwing his life away. A man who plays Quidditch while incapacitated is a man who will fly missions while incapacitated, as any big sister knows. And Alexander, like Persephone, had learned the art of self-sabotage early, though without the same finesse. Was it suicide, she wonders still, or just a love of danger? Did he realize how pointless the mission was, or was he drunk on the rhetoric of Mad-Eye Moody? Alastor's enthusiasm killed a lot of young men, most of them more to be regretted than Alexander.

She used to think her past was complicated, tragic. But with age one gains the critical distance to call a spade a spade. Dad was a tyrant; Mum was a cipher. Alexander, by seventeen, was a raging drunk. Persephone was the rebel who stood on a chair and said loudly and clearly that this was wrong, that this was not what a family ought to be, and afterwards escaped to New Zealand. And Minerva was the good girl who stayed at home to tolerate Mum's passivity and her father's wrath, to nurse the depressed and wayward Alexander through his drunken sprees, to emerge as the well-respected but not-quite-genius daughter of an embittered and never-quite-satisfied father, to bear alone the burden of that modest Highland bothy.

When the war ends, she'll take a leave of absence. She will go to Oceania, to Moutohora and Woollongong. She will go to Van Diemen's Land. When the war ends, she thinks, not now; when the war ends, which can't be soon.

Albus would let her go tomorrow if she asked. He's one of the few who knows.

Author note: In the Muggle world, Great Auks are (a) flightless; and (b) extinct. Still, I imagine Dumbledore may have some stashed away somewhere . . . one couldn't reasonably expect a three-pound barn owl to work the New Zealand-Scotland route.