Hotel hit squad Georgian House Hotel

Themed hotels can bring Hattie Garlick out in hives, but this magical London stay leaves her spellbound

Some dark magic is afoot. Travelling home from Hogwarts, my daughter and I find ourselves not on the Hogwarts Express, but on a Greater Anglia stopping service. In place of sparky students, our compartment is stuffed with young mug(ggle)s holding six-packs and alcopops. By the time we board the rail replacement service (markedly less speedy than the Knight Bus), the spell has definitely broken.

Which is a shame because our early Halloween adventure had proven unexpectedly charming. Themed hotels bring me out in hives, so I’ve always given the Georgian House hotel a wide berth. One of those small hotels that have spread like a certain virus through Pimlico’s white stucco mansions, its proximity to Victoria Coach Station, from whence coaches depart for the Harry Potter Studio Tours, led some marketing wizard to transform its basement into a suite of Hogwarts-inspired “chambers”.

But… my seven-year-old has just caught the Potter bug and the hotel is about to launch a new Enchanted Afternoon Tea for Halloween, so we packed our trunk(i)s, and jumped aboard the Flu Network (Circle line), having been given a stern warning from Warner Brothers that the hotel is not franchise-approved.

And thank goodness for that. I suspect its “unofficial” status is the reason it cast an immediate spell over me. The whole production is endearingly hand-spun. At the tiny check-in desk, the young receptionist hands us a room key hanging from a wrought-iron owl, plus a velvet purse filled with silver and gold coins. These, it transpires, are redeemable at the “wizard tuck shop” – a cupboard in the lobby filled with chocolate frogs, “head-popping” homemade shortbread and other treats. Her colleague disappears to set the scene so that when we are led downstairs to the Wizard Chambers, the Harry Potter theme is playing softly in the narrow corridor lined with old portraits, and the (fake) candles are flickering spookily.

The door to our room (39) creaks open into a large dormitory with stone walls, embossed ceilings, stained windows and – in the centre – an epic double, four-poster bunk-bed, hung with velvet curtains in the Gryffindor colours (red and gold). An archway leads into a second bedroom, decorated with suitably kooky antiques – mannequin hands hold lamps to walls, a heavy oak mantlepiece bears brass candlesticks and apothecary bottles.

For the avoidance of doubt, the ceilings are trompe-l’oeil; the stained glass a sticker. Kettle, coffee and tea are hidden in the antique wardrobe, while we find a TV behind the curtains of the four-poster. We have penetrated deep into the dark realm of the “themed” and yet… I’m charmed, not horrified. It helps that the rest of the hotel is resolutely un-so – a crisp, contemporary refuge from the kitsch that is sending my daughter into paroxysms of delight. We tiptoe down to the small restaurant, careful not to alert muggle guests to the wizarding world beneath them.

Then – the moment I’ve been dreading. The new afternoon tea menu is full of food puns: devilled eggs, cursed macaroons, dragon blood coulis… Alarm bells ring shriller still when it arrives in tiered stands shaped like owl cages, accompanied by a cauldron of bubbling dry ice. The seven-year-old audibly whoops. I close my eyes, send up a prayer, sink my teeth into a “magical mackerel mousse tart” and – what devilry is this? It is utterly delicious.

Next: a cocktail and mocktail “potions class”. Brightly coloured liquid ingredients arrive in test tubes. A parchment recipe instructs us to add “vapourised troll fat” to “revival mushroom compound” and watch it transfigure into a new neon shade. Dragon blood, werewolf fur and more is added to our crystal cauldrons to create a potion that looks fabulous and is, well… palatable.

It’s the little details that make this place genuinely charming. The waitress lends us witch hats, and reception gives us Harry Potter and the Philosopher’s Stone from its exhaustive DVD library. So, back in our chamber, we climb into the double bed, pull the velvet curtains around us and our TV, turn off the lights and create our own micro-cinema. It is spellbinding. The only omission is the lack of toiletries in our shower room. We’ll have to practise our summoning spell for next time. Accio, shampoo!

Wizard Chambers sleeping up to six guests cost from £290 per night, including breakfast