Bill Hayes was 48 when he moved from San Francisco to New York. His longtime partner had died suddenly, and after a lifetime on the West Coast, Hayes was looking for a place to reinvent himself. In New York, he found exactly that. Shortly after moving, Hayes begins a relationship with famed neurologist and writer Oliver Sacks. What unfolds from there could be called a love story, but not in the way one might expect.

In that vein, the subtitle of Insomniac City: New York, Oliver, and Me couldn’t be more perfect. While Hayes’ relationship with Sacks blossoms, so does his relationship with New York, and with himself after the tragedy of his former partner’s death. When not with Sacks, Hayes wanders the streets of New York, taking photographs and meeting the colorful, charismatic neighbors and fellow roamers who make the city buzz. “One thing I hoped to capture in the book was the two worlds I occupied in New York City. One world was confined to the apartment where we lived, it was a cocoon of creativity and discussion with a quirky, almost 19th century neurologist,” he says. “And then there was my life on the streets of New York. I spent a lot of time walking, on the subway, in taxi cabs, chronicling my life with strangers.”

These stories of strangers are mostly vignettes, one-off encounters, and serendipitous or comical interactions. A standard narrative thread relates many of these stories, but far more interesting is the way “raw” passages snipped straight from Hayes’ journals interplay (or don’t) with black-and-white photographs taken while wandering the streets. At first the pictures and the journal entries seem disparate, but that’s not really the case. “I knew from the beginning that I wanted the photographs to appear in the book the way I took them, so that they come up on the pages like you’re passing a stranger on the street,” Hayes explains. “Except for a couple of cases I don’t explain or tell the story behind the photographs. It should just have the feeling of being in New York City. I wanted the reader to experience that the same way that I did.”

In that sense, the journal passages and photographs serve as small moments of wonder viewed through Hayes’s keen eye. The Bill Hayes Cover photographs also, in some ways, serve as homage to his life with Sacks, who died in late 2015. “He got a big kick out of these pictures, in part because it was exactly the kind of thing he’d by terrified to do,” Hayes says. “Sometimes I would need to stop to take a picture, and  he would kind of marvel that I would have the balls to do that. He enjoyed it, and it became a really sweet part of our life. At the end of the day I could show him pictures I had taken and he would read to me whatever he had written. I think we cultivated that in each other.”

When Sacks is diagnosed with a terminal illness near end of the book, it’s hard not to feel heartbroken for Hayes in a story that, for him, is  bookended with loss. But that is what makes Insomniac City memorable: through it all, Hayes remains grateful, in awe of the world around him. “I’m a fortunate man, and I’ve had a lot of joy and unexpected kindness, especially from New Yorkers. That’s what I wanted to show and write about, because that has sustained me.”

Alex Layman is a writer living in Austin.