The best party guests know how to make an entrance: arrive when it suits, be dramatic and flamboyant and leave well before the end.
So it is when we arrive at night on a snowmobile at the Aurora Safari Camp on the banks of the frozen and snow-blanketed Råne river in Swedish Lapland.
Jonas (bossman) turns off the engine and, with no warning at all, the aurora borealis appears. Just like that.
The guest of honour, all whirling green shapes miraculously spread vertically for miles and miles, as if backlighting a mountain range. Dancing like ghostly apparitions, changing shape, changing colour then fading away.
It’s mesmerising and I’m not sure I have ever been so perfectly in the right place at the right time.
On a trip to Swedish Lapland (pictured), Kate Johnson takes a hot air balloon ride over blankets of pristine snow and silver birch and pine forests
It’s quite a welcome to this camp built among pine trees, about 25 miles south of the Arctic Circle. It moved to this north-facing location upriver last year and has added two new structures alongside its three ‘tent rooms’, so it can now sleep ten.
Inexplicably called cones (they are not at all conical), the new wooden-framed rooms are warm, cosy and shaped like 50p pieces with floor-to-ceiling windows and a roof panel, the better to gaze straight into the starry depths of night from bed.
The camp combines the best of the solitude, peace and otherworldly wildness of the extraordinary landscape, without being completely off grid (you can still check your phone messages).
Kate stays at the Aurora Safari Camp, pictured, which lies about 25 miles south of the Arctic Circle
It’s totally relaxed and set up for sociability, with wood-burners always lit, the kitchen permanently open and someone always around. Benches covered with reindeer skins surround the log fire on deck.
How could you possibly follow the aurora’s welcome? Well, here’s how — with a hot-air balloon ride.
While the Northern Lights can be seen from October to April, the window for ballooning, which needs high cloud and clear days, is from February to the beginning of April. Get a move on, in other words.
Watching the huge, inert shape lying carefully unfurled on the ground before being pumped with hot air and springing to life is strangely alarming.
Pilot Björn, navigator Jonas and I climb into the small wicker basket — hand-made in Oswestry, in Shropshire — and gracefully ascend to 500ft.
Björn is a cheery Swede who fell in love with flying as a teen and has clocked up thousands of hours as a pilot of planes and balloons over 40 years.
The wooden-framed rooms at the Aurora Safari Camp feature floor-to-ceiling windows and a roof panel, which allow Kate to ‘gaze straight into the starry depths of night from bed’
Kate Johnson travelled with Discover the World (discover-the-world.com), which offers four nights’ full board with dog sledding, Northern Lights and snowmobile excursions included, as well as transfers, from £1,334 per person. Hot-air balloon tethers from £210 per person. Flights from £330 direct from Heathrow to Lulea with SAS (flysas.com).
I’m in the safest hands, which is a comfort, as I’m not sure that when you’re airborne is the best time to be told no one can steer (I hear ‘control’) a balloon left or right; the pilot, instead, uses the speed and direction of the wind.
We have the skies to ourselves. Underneath us are blankets of pristine snow, silver birch and pine forests, and we spot the occasional moose lolloping through the trees.
It is surprisingly warm — and pin-drop quiet (when the crew aren’t giving the balloon a burst of hot air). You half expect to see the edge of the world curving away from you on the horizon.
Back at the Aurora camp, encouraged by two fabulous women holidaying there — one of them a devoted ice-bather and cold-water swimmer — I perch in the sauna that sits on the frozen river and then, to my complete amazement, step down into the icy water, with no hesitation. Twice.
It feels like another example of the wonders that this ethereal land delivers.