It was the last walk. I departed late, and had no time to pick up provisions, as on previous walks. I didn’t really want them anyway. I awoke early, hot, and anxious that I was getting sick. The day was daunting, as the stakes were high: fulfilment of the year-long project rested on this walk. I walked across the park in fog. My pack was unreasonably heavy, with stuff for a three-week trip to the US as well as the walk itself. The Piccadilly line had delays. I was still only at Kings Cross at 9am due to the delays. I was on edge.

Ultimately I arrived at Charing Cross only six minutes late. Tom was already there, waiting with Alice, Larena’s cousin, who was visiting from New Zealand. Alice seemed aware of what was required for the day, and we joked about stereotypes of Kiwi endurance. Indeed, she didn’t seem at all perturbed by the prospect of the day ahead. We hoped to make it out to St Albans, outside of the M25, the most ambitious walk of all. And for me, a personal goal of crossing the M25, which I hadn’t achieved on any of the previous walks of the year, despite having camped within earshot of its rumble. We all agreed that we had no time to lose on a short Decembers day.

We spent ten minutes redistributing our pack contents to mitigate the weight of my pack. I gave Alice a tent for her to use that night. And then we set off, passing the fourth plinth, up the side of the National Gallery, and into Chinatown. Tom and I compared notes on our recent experiences with cold-water swimming. A motorcycle passed with a notice saying “BLOOD” on the windshield. The texture of the streets were not in our favour, and we slogged a zigzag route out of the centre of London. After quarter of an hour we crossed Oxford Street, disconcertingly quiet so early on a Saturday morning.

We passed through more inner city streets, and onto Great Portland Street, the top of the BT tower lost in low clouds. I discussed electron microscopy of steel girders with Alice. The streets were an uninspiring wash of grey and low cloud; London in the winter, marked in every face we met. Tom and I traded reciprocally oblivious cultural references.

After more of the same, we reached St Andrews Gate into Regent’s Park. Roadie riders swooshed by us as we waited to cross the road. We crossed into the park, though I was disoriented, and didn’t recognize where we were. Sculptures lurked on the sides of the path. An angular white thing, some curvy organic structures in the bushes. The park seemed more overcast than the city streets had been. We walked into the centre of the park, then crossed diagonally over football pitches bordered by bare wintry trees. A short white dog stared at us expectantly as we neared the edge of the park.

The park bordered the zoo. A tiered pyramid just over the fence served as an unintended pigeon enclosure; it wasn’t clear what usually lived on the pyramid. We left the park, passed through leafy, central-London suburbia, and crossed a wide canal on a footbridge. A suspended structure lay to our right; part of the zoo. We walked up a road with nice 1920’s flats on our left, and Primrose Hill park on our right. At the top of the road we entered the park through a gate in the railings, and continued to climb until we reached the top of the hill. I struggled under the weight of my creaking pack, sweating, and relished the opportunity to stop at a porta-urinal, evidently placed for views of fireworks tonight. I questioned whether my body was capable of the day.

We left Primrose Hill and continued through a mix of elegant old houses and council estates, arriving soon into Belsize Park. The fog gathered, denser, as the day progressed. The compass directed us into a cul-de-sac as we entered Hampstead Village proper. A large Range Rover pulled up as we peered into the cul-de-sac. Tom talked with the woman at the wheel, but I didn’t catch their exchange. I presumed she wasn’t approving of our presence, but the conversation appeared civil. Finally Tom returned to us, saying it was worth a look. We walked in, but it became rapidly apparent that we’d have to backtrack. As we excited, the woman asked curiously where we were heading. “St Albans”, Tom replied quickly.

We retreated back to the main thoroughfare and were quickly back on track, with a short steep climb along a leafy road with steep old ivy-covered brick walls. To our right was the appendix to the Heath, wild and unknown. We entered it momentarily, hoping to find our way, but the paths conspired to eject us within a couple of minutes. Next, through mansion suburbs; huge old houses; old money. We continued through these streets, and were next funnelled onto a long road onward. Although I knew that we were still deep within London, the houses and space evoked the outer city. The long straight road continued until we hit a main road, a centre of sorts, with pedestrians and shops.

The centre was Golders Green, and the compass directed us to the tube and bus station. I was exhausted, and we paused for twenty minutes for a toilet break and for water and snacks. Tom and Alice walked ahead as I adjusted my bag, delaying shouldering it again. When I caught them we talked about Tom’s wedding, next year, and walks. Green, leafy, rural walks. Our way was a long, dull, wide road, with plenty of shops in grim buildings with ground-floor shopfronts. Sporadically we escaped into alleys behind the road, traipsing past garages and uneven concrete, but were soon returned to the thoroughfare.

At midday the long road delivered us to the North Circular. I recognized it as our route to drive into north London. The area was barren, concrete, heavy with traffic, grey and damp. I ran down into a wooded hollow to pee while Tom broke guidelines and texted Larena. She would try to meet us for lunch an hour later; she had been tracking Tom by GPS during the morning.

We crossed the North Circular, and passed the front of a Jewish Temple, with rows of pushchairs sheltered under the rim of the roof, then looped around the back. The temple was surrounded by men acting as either ushers or security. The road quickly became the harsh grey concrete and brickwork of suburban London: big houses, brown bricks, little grass, few trees, tamed hedges, drizzle.

We walked on. One road dipped momentarily into a small valley with a stream, ‘Windsor Open Space’, but we were soon back to suburbia. After a long road, I dropped my bag, and insisted on a snack. Kendall Mintcake. I wasn’t sure if I’d ever had one before, and it was good. A steady stream of orthodox Jews walked past while I ate. I said hello to one elderly man, who stopped to ask us where we were going. “St Albans”, we quipped. “Why?”, he asked. “A project”, we responded. “For whom?”, he astutely countered. “For ourselves”. All good questions. Then we walked on.

At the end of a cul-de-sac we were delighted to find a footpath into greenery, a golf course, the last one of the year. We struck out straight ahead but were quickly told to turn back — apparently we’d strayed, inadvertently, from the official footpath onto a golfer’s track. We backtracked for a minute to a bridleway which bisected the golf course, lined with tall trees. A cemetery lurked to our right behind spiked railings. We emerged onto a road at the entrance of the golf course we had just corssed, discovering that it had been Hendon Golf Club.

Then, a long straight main road with houses and football pitches. To the north we glimpsed a striking tall building on a ridge, rising from the trees with a green roof. Tom started to liase with Larena by text to meet for lunch. She was on her way, to Edgware. We continued a deathmarch along the main road toward Edgware, driven by the urge to consume miles, and eat lunch. My backpack continued to weigh on my shoulders, so very heavy.

We arrived at Mill Hill Park where we agreed to stop for our lunch. We perched on a wet log to eat. Dog walkers strolled slowly around the perimeter path near us, but the park was generally quiet. Soon, Larena bounced across the grass, having successfully tracked us down. We were somewhat in awe at her arrival, courtesy of the genuine delivery of one of the promises of 21st-century technology.

After resting, eating, and talking, we set out again across the park, stopping at a toilet in a bowling club as we left. It was almost 2pm, and we were conscious of how little daylight we had remaining. After passing through an alleyway between houses we were surprised to emerge onto a concrete footpath between fields, our first footpath through an illusion of countryside. To our right, a large country club, with a statue on plinth, out-of-place. Soon the path was over, however, and we were back on streets.

After walking through more damp city streets we reached the A1. A busy, exurban road with little sympathy for walking. A sign pointed “M25” — “5 miles”. Still far. We dropped onto a long straight suburban road with promising views to woods on the horizon, suggestive of imminently breaking free of the city, despite our continued trek through the ongoing suburbs.

We were channeled under a major road — the M1. I paused behind a parked truck before we continued, penned in between the motorway on our right, and an artery of railway tracks on our left. The road lacked a pavement, but traffic was light. Barren trees, rubbish, and security cameras decorated the roadside. The road led us into a ‘Welcome Break’ service station, a world usually entered only from a motorway by motor vehicle. Affirming this, cars quickly passed as we walked down the pavement-less road. Then, a police car accelerated past us, sirens blaring, triggering a moment of panic.

The service station world was distinctively un-London, and we wondered what would come next. The railway continued to our left; the motorway to our right. Roads leaving the service station seemed to funnel traffic solely back onto the motorway. Then, we found a service road, marked closed to the public. The interface of an awkward phase separation between city and country. We were thankful that staff presence would probably be at a minimum on New Years Eve. Could we attain escape velocity to get out; could we break out of the urban world and emerge, blinking, into the rural? I knew that sometimes this could be harder to achieve than you’d think, and we weren’t optimistic here. With only this option, however, we walked down the road, under the motorway, and into a works area. People were clearly present: there were cars and service vehicles parked. Expecting a yell at any moment, we slipped along the side of the site to its end. A series of poorly tied-together metal fences were easy to slip through, straight into a wood. We clambered up and away from the works area, congratulating one-another, and giddy with our final birthing from the city into a wood. We paused for a snack, conscious of the passage of time. It was 3pm.

We trampled through the wood, disoriented, in turns suspicious of the compass and our intuition. Neither seemed to help. We walked in one direction but were turned back by undergrowth and a steep incline. After working our way through the trees we found a track with red markers. We followed it one way, then our intuition pulled us the other, down a steep muddy slope. Surprisingly, no-one slipped in the mud. Finally, we emerged into fields, confident that we would be able to find a way onto the road that we intuited on the other side of a row of houses at the far side of the field. The fields have been spread with manure, but were scruffy in the winter, with bare trees, stubble, and unkempt borders.

After two endless fields we found a track leading to the road. The main road that we emerged onto had signs for the London Loop. We crossed the road, into a grassy space. Then, to our surprise, relief, and disappointment, we were back into suburbia, although it described itself as a village. We were glad to be back on track, albeit an uninspiring one.

We ricocheted down Tenison, Milton, Shakespeare, and Coleridge drives. Clean modern suburbs. A well-developed cul-de-sac looped us back, then soon, we crossed a park. A cat lurked under an off-duty ambulance. Then, down yet another long straight road, to be turned aside at a T-junction. Much to our surprise we were ultimately dumped out at Elstree and Borehamwood train station. I remembered from looking over possible routes on a map the previous day that this station was on the line from St Albans to London. I made a note that the station could be a possible exit route if we camped soon. But that was unlikely — it was still early, around 4pm, and we were all driven to walk further. Besides, we hadn’t seen any clear camping opportunities.

After the station we were sucked into the gravitational pull of a main road out of Borehamwood. The daylight was fading as we passed through spacious red-bricked suburbia. We exited Borehamwood into suburban countryside, with fields on either side. Soon we were hugged by a wood on our right. My feet hurt, and the group became silent, soldiering on, under duress as the day faded. After a mile trudging along the road we descended into another satellite town.

By the time we arrived into the centre of Radlett it was 5pm and completely dark, with Christmas lights illuminating the tidy town centre. Restaurants gloated at us. I rallied the troops into the train station, and we agreed to settle and eat, taking a rest as we gathered our thoughts. I checked trains with the attendant. A Thameslink train running straight through the heart of London could take me to Gatwick the next morning, leaving a little before 7am. The train was perfect for my plans—indeed, surprisingly easy. But I wanted to press on, despite the pain; I wanted desperately to cross the M25 by the end of the walk. We discussed plans among ourselves. The train timetables suggested that the walk to St Albans from Radlett was the same as our walk to Radlett from Elstree and Borehamwood. That had taken us an hour. I attempted to sell to the group that another hour would poise us to walk into St Albans the next morning; furthermore, we would break the M25 barrier that evening, something not accomplished on any of the previous walks. Everyone agreed.

After a pause we shouldered our packs and got back on the road. We walked through the remainder of Radlett, restaurants continuing to taunt us. As we reached the edge of the village, however, Alice’s feet gave up, and she couldn’t go any further. It wasn’t possible to keep going, so we agreed that we’d take the next available footpath and set camp as soon as we could. We were disappointed that we wouldn’t cross the M25, but Tom and I salvaged our goal by plotting to trek onward after setting camp to achieve the symbolic M25 crossing.

Ten minutes later and a footpath forked to our left. We followed it, down a sunken green lane, navigating through the dark and the mud with our torches. We were stopped by a dark pool of water across the sunken lane—a ford? It was too dark for us to tell, but we knew we couldn’t go on. We explored the field to the right of the track but it was intractably bumpy with tussocks of overgrown grass. When we clambered up the other side of the sunken track, however, we discovered an exposed ploughed field that, nevertheless, wasn’t overseen by any roads or houses, despite its immediate adjacency to the main road. We agreed that it would do, dumped our packs, and setup our tents. Occasionally a car drove along a track at the edge of the field, half a mile away, but by extinguishing our lights we were confident that we had escaped their notice.

After we were setup Tom and I walked across the field, back to the road, and continued our walk away from London. The journey to the M25 was longer than we’d expected. Eventually, however, we reached our goal. The motorway turned out to be somewhat anticlimactic: there were no on-ramps, just a bridge over the motorway. A bridge you wouldn’t even notice if you were driving under it. And it was cold. Cars passed continually in both directions along the M25. We walked ceremonially to the far side of the bridge, where the road continued, much the same, away from London. We supposed that it would continue for another couple of miles to St Albans. We took a few minutes to appreciate the closure of the project, taking in the flow of cars beneath us, then turned and set off back to camp.

We cooked. The others shared a bottle of wine. Our setting was cold and unglamorous. After dinner we crossed the path into the tussocky field, and Tom set off a large tub of fireworks. They were fairly serious, and a faint thrill came as the tub fell to its side in the midst of the battery, sending the final set of rockets into the sky at an angle.

We headed back to our tents, and by 9pm we were all tucked up to sleep. Everyone was exhausted, and no-one had the energy to stay up to see in the New Year, despite jokes that we would.

I slept deeply that night despite discomfort. At 5am I was woken by my alarm. I quickly packed up, energized, woke Alice to retrieve my sleeping pad, bade her farewell, and whispered goodbye to Tom and Larena. Soon after 6am I was at Radlett train station, picked up a coffee, cancelled my contingency taxi, and was on the Thameslink Train. By 8am I was at Gatwick, 10:30am I was on my plane, and that evening I was in Salt Lake City. I slept deeply, my mission accomplished.