'No, Severus,' the Headmaster said. 'You can't possibly teach two full-time workloads.'

'Since the start of my teaching career, I have been teaching thirty-six hours out of a thirty hour teaching week, plus lesson preparation and marking,' Severus pointed out. 'If I was unable to cope with being in two places at once, I wouldn't be in this job. And only a few years ago, you allowed a thirteen-year-old to use a time-turner in order to study every course on the curriculum.'

'Because it was the best way of letting her find out that she didn't want to,' Dumbledore replied. 'But people are bound to notice something going on if you're teaching Potions full-time and Defence Against Dark Arts full-time, aren't they?'

'Did they ask questions when I had to cover Remus Lupin's classes when he was "unwell"?' Severus retorted. Of course they hadn't. Children didn't see teachers as human (but then, some, like Remus, weren't), and they were too busy complaining about having Defence Against Dark Arts lessons covered by their awful grumpy Potions teacher instead of that cool Professor Lupin, and being set homework, to ask their friends who had been in a Potions lesson at the same time who had been in charge there.

So many wizards had been killed in the first round of the war against Voldemort, or had been imprisoned for war crimes (not that Aurors who mistreated prisoners, or judges who sent them to Azkaban for years without a trial, were imprisoned, of course, because they were on the side of Good)… Anyway, so many wizards were gone that for the last fifteen years, Hogwarts had struggled to recruit more than one teacher per subject. But that didn't stop there being six hundred wizarding children between eleven and eighteen (many of them orphans, or with parents who were ill or in Azkaban).

The exception, because they had been born when the war was at its bloodiest and many people either didn't risk having children, or couldn't save their lives, was Draco's year. Or, to put it another way, the year containing Longbottom whose toad escaped several times per lesson, Granger who had doubtless got an 'Outstanding' in all her OWLS but could be genuinely outstanding if she could only be bothered to think for herself instead of just memorising all the textbooks, and Potter who had made no secret of hating him ever since they met, and who had resisted all Severus's attempts to teach him anything at all, particularly in that fiasco of an attempt at Occlumency lessons last year when he had looked into the Pensieve where Severus had put his most appallingly humiliating memories out of reach, and who had been the reason Lily died…

Well, no, all right. Lily had died because he, Severus, had overheard a prophecy and had taken it to the Dark Lord, and the Dark Lord had decided it referred to Lily's son and set out to kill him, and Lily, like any loving parent, had died rather than allow anyone to harm her son, and the ungrateful little wretch seemed determined to squander her sacrifice by getting into hair-raising, hare-brained adventures which were perpetually nearly getting him killed…

All right, be dispassionate about this. Just treat him the same way as any other exasperating brat who needs constant supervision. Hah, super-vision – that sounded like the power to see through walls and invisibility cloaks. The power to see what the little brats were up to wherever in the castle they were. Like that map James Potter and his gang had come up with so that they could be sure of ambushing Severus when he was alone – not that he'd known that was how they did it, at the time, of course…

'Severus? Are you still there?'

He'd been on the point of dropping off, he realised. Which was deeply embarrassing, especially in front of a man who was still capable of putting in a good day's work at over three times Severus's age. Well, all right - three times his official age of thirty-six, calculated from when he was born. Chronologically, he must be in his fifties by now, allowing for all the extra hours he'd put in with the time-turners. What with teaching, lesson preparation, marking (especially with Granger's essays that were usually at least twice the length requested), housemaster duties, creating whatever potions were needed, and spying on Voldemort while convincing Voldemort that he was spying on Dumbledore, and having to rush out in an emergency to rescue three of his least favourite pupils from being trapped in the Shrieking Shack with a werewolf and a psychopathic mass murderer, it just wasn't possible to get everything done otherwise. It wasn't as if he was even using the time-turners to gain any extra time for anything he might have wanted to do, like research, or reading anything that wasn't directly related to work, or sleeping, or eating lunch, or shampooing hair that, in his officially-thirties-but-actually-fifties, still seemed to need washing as often as when he had been a teenager.

But what choice was there when…

'So if you teach Defence Against Dark Arts this year, I'll see if I can persuade Horace Slughorn out of retirement to take over Potions,' Dumbledore continued. Severus, much as he had liked having old Sluggie as a housemaster, felt like retorting that the only good thing about having him as a Potions teacher had been that the lessons were so dumbed-down that they had provoked him to experiment on his own with improvements to the lessons. But he was too tired even to get the words out.

'And Severus, if you're going to go on using the time-turners to buy enough time for everything, can I please make a personal request?'

'Yes, Headmaster?'

'Please use them to get some sleep!'