When I start with a new idea for a novel, I usually begin with a character, but “The Last House Guest” was partly inspired by the idea for the setting: a vacation town. And from here, my mind went straight to Maine.

I have always loved Maine, where my dad grew up. When I was a child, our family vacation each summer meant driving from New Jersey up the eastern seaboard, eventually ending in Bar Harbor, where we’d spend a week hiking and exploring. As an only child, I was allowed to invite my best friend to come on these yearly trips.

I had been thinking a lot about these memories while I contemplated the new novel, but I realized I hadn’t been back in years. Decades, actually. I live in North Carolina now, and the trip to Maine is no longer a one-day (very long) car trip. So when I was working on an early draft of “The Last House Guest”, I asked my family if anyone wanted to join me on a research trip to Maine. Though the town of Littleport is fictional, I wanted to make sure that it felt authentic.  And, I wondered whether I could trust my memories.

And this is how, a few summers ago, I ended up spending a week with my parents, my husband, and my two children, driving up and down the coast of Maine in one minivan. We started in Portland, found my dad’s childhood home in Augusta, then drove both south and north, stopping at so many picturesque towns along the way. We hiked, we explored, we ate a questionable amount of lobster rolls. We ended in the same place we used to visit when I was younger, hiking the same trails I’d last followed as a teen, visiting the same restaurants, the same streets.

But there were things my parents pointed out that I couldn’t remember. And there were other things I could feel so clearly in my memory that I couldn’t put in context now.

The visit made me think a lot about experiences—which memories stick, and why.

This was my memory of my favorite hike: My best friend and I racing ahead up the trail, with my parents following behind. The exhilaration of the rungs and ladders and stunning drop-off views. How you could turn around at any point and see nothing but rock and air and ocean. Or how you could stand on a bridge and feel your stomach drop, just from looking down. In my memory, I can still sense the adrenaline.

As it turns out, this same hike—as a parent with two children of my own—was absolutely terrifying. I did not look up to take in a single view. I did not look down over the edge of the bridge. I did not try to see the ocean. I looked at my children, at where they were placing their hands, their feet. I called out instructions. I counted the steps until it was over. In my memory now is the sound of my heartbeat resounding inside my head.

At the end, shaken with a new type of adrenaline, I turned to my mother and asked how that hadn’t been terrifying for her when I was younger. She told me, with a small smile, that it was.

When we started this trip, I had been thinking about the way these “vacation” towns could be viewed from two different perspectives: as an outsider, who visits in the summer, or as an insider, who lives there year round.

So the characters of Avery and Sadie grew from this tension.  Sadie, the daughter of the wealthy Loman family, who own most of the vacation rental properties in town and live in a stunning home on the cliffs overlooking the ocean; and Avery, who has spent her entire life in Littleport, and, at the start of the story, is living in the Loman’s guest house, working as their property manager. Their intense, unusual friendship became the heart of everything to follow.

But visiting again as an adult made me aware of the other layers to perspective. As the vacation progressed, I came to think about the way one person can view a place from two different perspectives. Because that’s what I was doing. One person, two perspectives. The only variable was time.

This was the moment when the story came into crystalline focus, tightly fixed on Avery: on one character’s relationship to a place that changes over time. One character who feels like an insider at one time, and an outsider at another.

Avery’s story begins with the death of her best friend, Sadie—a moment she hasn’t moved past a year later, that she keeps returning to in the story. The more Avery uncovers in the present, the more the past reveals itself, shifting and resettling, into a different picture.

Fueled by Avery’s search for the truth, “The Last House Guest” became the story of how perspective and relationships and identity constantly and inevitably change, with time. As does our understanding of the past, and what might be possible in the future.

I hope to return to Maine again soon. Being away for so long made me realize how much I’d missed these family trips. I left feeling there was still so much more to explore—and years of new memories to make.