That is a matter between Severus Snape and myself
Chapter 3: Alastor Moody
The Dursleys had stopped their packing when he walked into the house, even though he'd told them to get on with it - after all, they needed to get out of Britain as fast as they could. If he knew anything of Voldemort's methods, by five minutes past midnight on the 30th of July there wouldn't be one brick left standing on top of another at Number 4 Privet Drive, Little Whinging, so Harry's Muggle relatives needed to get as far away from the Death Eaters as they could – Australia, perhaps, or Patagonia, they might – might – be safe there.
They'd stopped their packing and huddled together on the sofa while he waited for Harry, the poor bloody Muggles were harmless, so he'd ignored them, rolled his magical eye around – constant vigilance, and the house must be under continual surveillance from Ministry spies and Voldemort's agents, probably one and the same, because the rot goes right through the Ministry. Voldemort - and maybe his chief lieutenant – alone know the names of all of the Death Eaters, but he'd bet a stack of Galleons there are plenty of Ministry officials amongst them, even Aurors, and he doesn't trust anyone who isn't an Order member, he doesn't trust anyone who hadn't given Albus Dumbledore their personal oath of loyalty.
And the neatly taped and labelled cardboard boxes piled by the front door are a reminder that Harry is going to have to travel light – wand, toothbrush and change of clothes – because as soon as he's of age Voldemort is going to declare open season on Harry Potter, set his Death Eaters to hunt him down and drag him before their Dark Lord for the coup de grace, and Harry is going to have to shift from safe house to safe house until the Horcruxes have been found and destroyed.
Horcruxes! As soon as he'd heard the word he'd instinctively he'd known that they are Dark magic, the very Darkest kind of magic, and they weren't going to be easy to destroy, not if Dumbledore's blasted right hand was anything to go by. He'd agreed with Snape – they couldn't risk letting Harry handle them, he might be fated to be Voldemort's executioner but he wasn't an experienced curse-breaker, and they'd have to find another way. Snape had suggested the Muggle way, and he had to admit that Snape knew his stuff, because the Windscale nuclear reactors hadn't been used to dispose of dangerous magical artefacts since before Snape was born - the Ministry hadn't used the place since that unfortunate fire in the '50s.
The first thing he'd done when he walked through the door was to check on Harry, and he'd been pleased to see that even in the shower the kid had both his wand and the Muggle weapon that Snape had taught him to use close at hand - Severus Snape and Harry Potter, Albus Dumbledore's killer and the Boy Who Lived, thick as thieves less than a month after Dumbledore's funeral, who would've believed it? He couldn't work that one out and he'd given up trying – and he'd had to stifle a grunt of amusement when Harry had come over all solemn and Dumbledore-ish and told him that his reasons for trusting Snape were a matter between Severus Snape and myself.
Prowling up and down in the Dursleys' sitting room, he'd mulled briefly over what he'd seen in the Pensieve, the memory that Snape had used to convince them that he'd killed the Headmaster on Dumbledore's own orders, and he'd thought, Snape was genuinely loyal to Dumbledore, Dumbledore definitely had some kind of hold over the nasty bastard – but what could it have been? And Harry seems to have the same kind of hold over Snape, from what he's seen of the two of them together. But maybe it's no more than the prophecy - Snape is a survivor; he knows the whole of the prophecy, knows that Harry will have power the Dark Lord knows not, and power of a kind that Voldemort doesn't know about must be something really toxic, really deadly. And that's an encouraging thought, when the odds seem stacked so high against the side of the Light – Severus Snape, Voldemort's right-hand man, has worked out which is going to be the winning side, and he's taking care to keep sweet with the Chosen One.
When Harry comes down the stairs there's no time to waste with idle chit-chat, it's time they were off; Harry has a rendezvous in London with Snape this evening, and it's going to take a while to get there, since he takes no chances of being followed - he doesn't take any chances with the life of the Chosen One, the weapon against Voldemort.
He'd wondered why Snape wants to see Harry, it must be something really important for Snape to risk a meeting, but he hasn't been told and he hasn't asked, because it's better if he operates on a need-to-know basis - what he doesn't know he can't tell. But he can't help wondering if it's something to do with Slytherin's locket; he's made discreet inquiries at every Muggle pawnshop within five miles of Grimmauld Place, because it's the kind of thing that Mundungus Fletcher would off-load onto a Muggle for quick cash. No luck, though, but Dung will be out of Azkaban soon, and then they'll have a little chat ...
He'd held Harry firmly by the arm and they'd Apparated with dizzying speed to half a dozen locations to shake off the expected pursuit – Side-Along Apparation, because Harry wasn't yet up to Apparating to a place he'd never been to before. And then they'd nipped into the Underground and finally caught a Muggle bus, Muggle transport was a good way to check that you weren't being followed, most wizards or witches who weren't Muggle-raised had never used an automatic ticketing machine in their lives, and it was easy enough to give them the slip in a crowded railway station while they were fumbling for coins.
So now he's lurking against a wall, protected by his Invisibility Cloak and a mild Muggle-repelling charm, across the road from The Pink PussyCat Club – not a bad choice, a bar for Muggle queers in the middle of Soho is the last place that anyone is likely to be looking out for Severus Snape or Harry Potter.
But Snape is late, there's no sign of him, has he run into the Aurors? Or has he finally slipped up, has he been caught out lying to his Dark Lord? And if Voldemort has finally cottoned on to the traitor in his ranks, how long have they got before Snape breaks, tells everything he knows - and they hear the crack of a dozen Death Eaters Apparating into the street?
He can sense Harry stirring restlessly next to him – but they can't wait much longer, if Snape isn't here in one more minute, he's going to Apparate the pair of them away to safety.
Then a bus stops – and when it pulls away, Snape is standing on the footpath outside The Pink PussyCat Club, so Harry slips off his dad's old Invisibility Cloak, dodges past the traffic and walks through the front door.
He settles down to wait for Harry, and to watch every person who goes through the door, though he knows that it's really just out of long-ingrained habit, because if Snape's Death Eater mates are going to crash the party they're more likely to use the back door – and they won't knock first. Yep, if Snape's friends do turn up, the first he's likely to know of it will be the bursts of green and red light flashing through the front windows of the bar – and the terrified screams of the Muggles.
Snape's friends! He snorts a little at the thought, because there's no honour among thieves and no friendship amongst Death Eaters – and then he thinks, Snape went to an awful lot of trouble to get Lucius Malfoy's boy out of harm's way, and that's how he got suckered in to the Unbreakable Vow in the first place, don't tell me that vicious son-of-a-bitch actually thinks of Lucius Malfoy as a friend!