We only turned off the gravel track 20 metres ago, but the Defender has already managed to get cross-axled, leaving the offside front and nearside rear wheels thrashing around aimlessly in the air, desperately trying to find grip where there is none.
I back off the throttle and apply the brake with my left foot, just enough to load the differential and help split the torque between the wheels, and the 90 crawls forward. It's a crude version of traction control, but it works.
I'm on the Ardverikie and Alvie estates in the Scottish Highlands. They've almost every conceivable type of terrain - and cracking views to boot - to make the ultimate off-road trip and show just how good a Defender is.
Even getting off the gravel track at the start of our trip is less than easy. A large drain beside the track is steeper than the Defender's approach and departure angles will cope with, so we have to make the angle less severe using a narrow wooden bridge and waffle boards.
Clumps of tussock grass flank the lightly defined route. A ditch, deep enough to cause problems, sits to my right and the ground to the left is marshy. There's only one line and I must nail it.
Tracks left behind by quad bikes highlight obstacles and show where the ground is softer. I've dropped the tyre pressures. Keeping rolling will be the key.
The peat is soft, but there's plenty of traction. A bit more momentum will be required where the ground gets softer so we scope places where I'll be able to stop the 90 safely and, more importantly, get moving again.
I clear the soft ground and pick my way up a deforested hill, stopping for a tree that has fallen awkwardly, just blocking my path. There's just enough room to limbo under it, but we trim a couple of branches to protect the bodywork from harm.
The tree was just before the point we need to turn further uphill. I pull away, smashing the driver's door mirror on a branch we hadn't removed, and try to turn. The tyres slide in the greasy soil and the treads clog up. I start to slew sideways and end up in a ditch with my bumper wedged against a bank, unable to reverse, with the wheels turned on full lock. This won't be the easiest recovery I've done.
I break out the recovery kit from the back of the 90, but with the nose of the vehicle pointing downhill opening the spare-wheel-laden rear door against gravity is hard work.
We pick one of the few remaining trees on the hillside, run the winch rope up to a pulley block and back down to a recovery point on the Land Rover - there's no sense in putting undue strain on the winch motor.
The rope starts to wind on the drum and becomes taut, and the front of the 90 starts to rise up the bank. I engage Drive to assist with the climb. Once the rear wheels are up the bank as well, I stop the winch and re-spool the rope.
I aim slightly downhill to build up a little momentum then make a gentle turn up the hill and park squarely on a bare slab of rock.
Into the valley
We ease the Defender 90 through a gap that has been cut in fallen trees and down the other side of the hill. It's slippery, with just a thin veneeer of mud sitting on top of the rock. A steady descent is required.
I make it safely to the bottom and along a terrace track running down the hill. More trees have fallen across the track, but it looks like there's just enough room to get the Defender under. Soon we're at the edge of the river feeding Loch Laggan.
We need to cross the river, but a steep drop off the beach sits ahead of us. I select first gear low-range and ease over the bank's edge and down the 45° slope.
The sand below the front wheels starts to give way, flattening the drop slightly and I accelerate slightly as the nose plunges into the cold water.
Extreme side slope
We clamber up the bank and out. Then comes a boggy area with just enough room to get a Land Rover along a bank between it and the trees.
The front tyres let go first and the Defender starts to slide sideways into the bog. I engage the rear locker and steer upwards, but it's to no avail and the 90 slides down, with the passenger panels pushing into the soft soil and stopping the vehicle from rolling over.
We call on the winch again. This time we wrap the tree strop round the massive root of a sturdier tree to pull the 90 up and out of the peat. The 90 slowly climbs out from its soggy resting place and on to terra firma.
A steep climb follows before we drop down to the river again for another crossing. We're slowly gaining altitude and the river bed is becoming rockier. As we get higher, the river gets narrower and the water is correspondingly deeper, splashing over the bonnet as we drop in.
We're going to be wild camping, but have to get to an appropriate camping spot first. We plunge into darkness among the trees, there's no light to the side and I drop the left-hand wheels into a bog. We grab the winch rope again and haul the Defender out.
With the 90 extracted I pay a little bit more attention to the route and we don't get stuck again, breaking out of the trees near to a river and a suitably flat site for a camp.
The river provides water for cooking and the nearby trees provide a little shelter from the wind. It's going to be a noisy night, though - the wind and the river are both vying for our attention.
Head for the hills
Breakfast is cooked over gas and we break camp and re-pack before heading back into the woodland. Tightly packed trees cause steering issues for the Defender. I rub the gutters along the bark as I carefully pick my way through the forest before dropping into a water-filled gully.
There's just enough room for the Defender to get through. Branches scrape along the bodywork and I get to the end only to find the Land Rover is just too wide to fit through the gap formed by two trees. Luckily I've spotted an alternative exit a little further back.
A steep hill takes us upwards through another forest before we drop into another rock-strewn valley, zig-zagging down the valley side and across another stream.
The climb is getting steeper now and we break out of the tree line and on to the mountainside.
Water running down the track has eroded sections and the tyres scrabble for grip on the loose stones.
There are no tracks to the summit and nor do we want to leave any. Slow and steady with no wheelspin should get us there without any environmental impact.
This is, for me, the most nerve-wracking section of the drive. Get this wrong and it'll take years to recover.
On top of the world
The thick foliage mat takes the weight of the Land Rover and we make it to the cairn at the summit without disturbing the ground at all.
With fantastic views in front of us over the Monadhliath Mountains, and behind us towards the Cairngorms, this is a stunning place.
The Defender has shown just how good it is. Unfazed by anything we put in its path - mud, rocks, trees, sand, water - it just kept soldiering on.
The full story can be found in the January 2016 issue of LRO. Download a digital issue, or order a back issue by calling 01858 438884.