I smile, though I’m smarting because most of the night was spent arguing with G, who’d come over an hour later than he said he would. I called him on it and it had caused a big fight, which ended up being the prelude to several rounds of sex. This had begun to feel like a pattern.

“What’s up?” I ask.

“We’re going on a visa run, come with us!” As a condition of our respective tourist visas, we’re required to leave the country every three months. The easiest way to do so is to take the ferry from Buenos Aires to Colonia, a tiny, charming Uruguayan city just across the Rio de la Plata.

“Oh okay, sure. Give me a sec.”

I’m hungover and exhausted, but I rally, and soon we’re aboard the high-speed ferry—the Buquebus—and rocketing across the churning brown waves of the river. The Rio de la Plata is an unlovely body of water. At 140 miles, it’s the widest river in the world, and being in the middle of it feels like being at sea. The river is an estuary, a meeting of the Uruguay and Paraná Rivers that empties into the Atlantic, meaning it’s never anything but the color of mud, obscuring everything below the surface.

We dock in Colonia and have our passports stamped.

“Let’s show Liz the historic district and grab some lunch down there,” Edward says, taking Cali’s arm. I’m the only one who’s never been here.

“Oh yes! It’s only a short walk, and there are some incredible ruins. They dug a whole little slice of the seventeenth century out of the hillside.”

We take photos by the Portón de Campo and continue on to the Calle de los Suspiros.

“Ah, this is my favorite street in the district,” Gemma says. “The ‘street of sighs.’ People mistake it for a romantic reference—that the sighs are lovers’ sighs—but really it was named for the sighs of the slaves hauling stones up from the wharf to build the town.”

As we walk, Gemma continues on her historical tour of Colonia with Cali, and I fall back with Edward. We walk in easy quiet, but at some point I realize he’s looking at me from the corner of his eye, smiling curiously.

“You know,” he says, picking his way carefully through the uneven cobblestones, “you don’t really look like a ‘Liz.’ What made you choose it?”

I stop in my tracks and meet his gaze for a moment that unfolds into an eternity. Possibilities race through my mind, that I’ve misheard him or that he means something other than what I think he does.

“It’s my middle name. Elizabeth,” I say finally, looking out at the harbor. The sunshine is sparkling off the river and the outlines of our friends are thrown into sharp relief.

“And Sullivan?”

“My mom’s maiden name.”