Early morning becomes mid-morning and then late morning and still it rains. It's also still cold, so we spend every moment burrowed in the sleeping bag in rain jackets and rain pants and fleece hats, trying to keep the heat from getting away. I don't eat anything, I don't drink anything, and I don't do anything. I just lay in bed with the same depressing thoughts that spooled and swirled last night running through my head over and over and over again. I know that this trip is over, and soon. It's just a matter of where and when and how we move on to whatever's coming next.

But that end can't come in the middle of the Great Pond Mountain Wildlands. We have to move, whether we want to or not. When a break in the rain comes some time after noon, we pack up, load up, and head back to the wet and windy bends and hills of Highway 1. For the first time I can remember, I ride on a long-distance bike tour without stopping to take notes or take pictures or even reflect within my mind about what's happening around me. None of those things matter now. Today feels like some kind of funeral procession, a moving meditation on an important chapter of my personal history that's about to come to a close on terms I never could have imagined. I have no desire to write about it, no desire to remember it. It's one of the worst days of my life.

And then it gets worse.

Kristen almost always rides in front of me. It's what we've become used to after almost 7,000 miles of cycling together. It helps keep us moving at the same pace. It lets me make sure we're both feeling good. It puts me in the position of lookout when it comes to watching traffic speeding toward us from behind. And it turns me into a line of defense between that traffic and Kristen. That's how I like it. But because Walter likes to be able to see both of us, to make sure that his pack is still together and accounted for at all times, we've switched that up on this trip. I've gone first and Kristen has trailed close behind.

But old habits die hard. Soon after we cross over the Penobscot Narrows Bridge, just beyond the town of Bucksport, Kristen pulls ahead and I fall back. Walter cries a bit in the beginning when Kristen disappears from his view, but soon he quiets down, he stops squirming about, and we continue on to the west in our very own train of sorrow. We're all cold and wet and sad about the state we're in, but we have to keep pushing because we aren't yet in a place that makes stopping possible. We continue on with Kristen leading our group for another five or six miles before I ask to pull off to the left side of the highway in front of a closed cafe to drink some water and let my legs rest.

As I stand over the bike, Kristen pulls alongside and opens the cover that sits on top of Walter's crate. She explains what happens next:

A fraction of a stunned second passes as my brain tries to believe what my eyes are seeing.

"Jeff!" I call out. "He's gone!"

It's all I can manage to gasp out before jumping on my bike and letting the adrenaline of panic push me back the way we came. A flood of terrible thoughts of hurt and death and fright and so much guilt run through my head. Then time slows down as I notice Jeff passing me. Suddenly all I can hear is the sound of my own hyperventilating breath as I watch first his calm and determined face, then the extended length of the cargo frame, and lastly the empty crate go by. Just as suddenly time speeds up again and I can hear the rushing cars and wind and know I have to get it together. I cross the highway to ride up the shoulder on the other side of the road, the side we had just come up, analyzing how long it had been since I had last noticed Walter in the crate, searching the ditch for any speck of white and calling his name.

Here's what happened: Walter no longer saw Kristen behind us and he decided that he needed to go find her, to bring his pack back together. He shouldn't have been able to do anything about it. But somehow he managed to unclip the pair of carabiners that held him from climbing up onto the edges of his crate. He also somehow managed to force himself through the cover that sat on top of the crate, the one that was strapped into place with bungee cords. It turns out the reason he seemed so quiet and relaxed was because he was no longer with us.

Kristen's assessment of my expression is half right; I seem calm. And I guess in some ways I am. My response to this kind of panic is measured reason, because I know that a full-scale freakout or meltdown won't solve the problem. But at the same time my mind runs through a quiet loop all of the terrible things that could be waiting for us on or near the highway that lies ahead. Walter could be half a mile behind us or he could be five miles back; we have no idea. He could have broken his legs or smashed his teeth or broken his jaw from jumping off the back deck of a cargo bike onto pavement at ten or twelve miles per hour. He could have run in front of a car and be dead already. He could have shot off into the trees or bushes alongside of the road out of fear or in an attempt to find us, in which case tracking him down will be almost impossible.

Of course he could be safe somewhere, sitting calm at the side of the road waiting for us to return, or hanging out in front of a stranger's house. But my mind doesn't focus on the positive outcomes. All I can think about is what kind of horror waits for us. All I feel is an outpouring of sadness and guilt and a level of concern greater than any I've known in my life so far. Our worst-case scenario has arrived.

A mile down the road I stop as Kristen charges ahead. I stop because I realize that I should check my phone. A free-ranging purebred West Highland Terrier isn't a common sight along the shoulders of Highway 1 in rural Maine. There's a chance he's already been found, in whatever state that might be. And if he's been found, someone is almost certain to have called the phone numbers listed on his collar tag.

It turns out this is where all of our questions and fears are put to rest. I have a voicemail message. When I check it, the voice of the woman who left the message tells me that she found Walter, that he seems healthy and happy, that he came right up to her, and that she has him at her house. I dial her phone number at once, thank her in every way I know possible, and we agree to meet at the intersection of the road where I'm standing over the bike talking to her. Our saga is about to come to its best possible conclusion. We're getting Walter back and he's going to be just fine.

But our savior never makes it to me. Kristen explains:

I'm preparing for the worst, so when a car pulls off into the shoulder I only think, "They'd better get out of my way; I don't have time for this." Then I see the outline of his furry head, looking out of the window from the vantage point of the passenger's lap. The worst day of my life has just become the best. I carelessly drop the bike in the shoulder, run up to the woman getting out of the car with my dog, and burst into tears as she puts him in my arms. All I can say is thank you over and over again.

I ride up the road another mile or so and find the other two-thirds of Team Hawthorne waiting for me. They're both a little wetter than the last time I saw either of them, but now much happier. Our worst-case scenario, our greatest fear, our nightmare — it's all over now. We're together once more.

With me back up front and Kristen keeping her eyes locked onto the crate we continue on to the closest campground. We don't want to keep going, but we have to get there soon because darkness is coming. The highway takes us through the small town of Searsport and then about a mile beyond. When the large sign for the beachfront campground appears we take a hard left and rumble and rattle down the long gravel driveway. We stuff our faces with the food we bought at the grocery store back in Bucksport and take long hot showers to ward off the cold and wet of the evening. When we come back together in the tent we talk about what we're thinking. We both want to keep going; we don't want to stop; we want to ride across America, together, all three of us. But our conclusion grounds itself in reality: this is it; the trip is done. Walter can't handle it, and we won't drag him along with us for the next three or four months against his will. All that's left to do is figure out what direction our life will take next.

In the early morning, with the first light of the day shining in through the rain fly, we talk about pushing on. It won't work with our current setup. This we know for sure. I offer to let Kristen ride ahead instead, with Walter and I traveling behind or in front of her in the van. But we both agree that we want to make this trip together, the three of us, on the bikes, under our own power. We talk about shipping the bikes back to the West Coast and spending the summer traveling in the van instead of cycling. We talk about making our way up to Washington State, buying a sailboat, and setting off on new adventures there. We talk about a lot of things.

Then I turn to Kristen and say, "Well, we have one last shot."

I open up a browser window on my phone and show her an item for sale on Amazon. It's a Dutch-made trailer called the DoggyRide. I read about it a few times several years back. It's designed for small dogs like Walter. It has two wheels for stability and a full cover to protect him from bugs and road debris and rain. It has a latching system to keep him from ever jumping out again. It has the best reviews of any dog-related product I've ever seen. It costs just under two-hundred dollars. If we order it right away and choose overnight shipping we can have it some time tomorrow.

It would also mean more weight and more resistance to pull — and Kristen would have to pull it because the cargo bike is already crazy long. It would mean more width to manage on the narrow, shoulderless roads of rural America. It would mean adding unproven tires and wheels and a bunch of other parts that could break and strand us in the middle of nowhere. And there's no guarantee Walter would respond any better to it than the cargo bike crate he couldn't stand. It could be a huge waste of time and money and effort.

But it's our best hope.

It's our only hope.

Five minutes later the decision is made. We're in.

Five minutes after that, credit card details have been given, a shipping address provided, and confirmation emails and UPS tracking numbers received.

And then we wait.