Election Day 2018 is just around the corner, and that means planning for election day coverage in the WGBH newsroom is in full swing. It also means that, like clockwork, our managing editor, Jeff Keating, once again came knocking on the Curiosity Desk's proverbial door. Each election day, Keating monitors the hour-by-hour election returns from the city of Boston, and there's been a question that has been nagging him for years.

"There's this one funky little precinct where the number is mostly zero, but maybe one or something like that. And it got me wondering what is with this precinct that has only one voter — or no voters — year after year after year."

For answers, I headed to the election office at City Hall. Head Assistant Registrar Sabino Piemonte explained that state law dictates all Massachusetts cities and towns redraw their municipal electoral maps once a decade, following the federal census. However, "back in 1920, the city of Boston was exempted from redistricting," said Piemonte. "To remove that exemption [would take] an act of legislature."

And so, in 2018, Boston’s precinct lines are at best anachronistic and quirky; at worst inefficient and outdated. However you see it, what remains is that funky little precinct: Ward 1, Precinct 15 — Boston's so-called "phantom electoral precinct." It encompasses the Boston Harbor Islands. But does anyone actually live on the islands?

"Ward 1, Precinct 15, as I know it, is comprised of two addresses," explained Piemonte. "0 Thompson Island and 1 Long Island."

For years, a recovery center and homeless shelter were located at 1 Long Island. Despite low turnout, dozens — sometimes hundreds — of shelter residents over the years were registered voters. But when the facility closed in 2014, those registration numbers started dwindling. The 12 voters still officially listed on the books are all inactive, and will be purged after this election if they don’t vote.

As for 0 Thompson Island? It is home to the only to active voters left in the precinct. So what happens at such a curious address, and who are these two voters? I headed to Thompson Island to find out.

As I disembarked from the ferry after a 20-minute journey from South Boston, I walked up a gravel path through a rolling, grassy hill. What came into focus as I crested the hill was a campus of historic brick buildings. There are classrooms, dorms, a science lab, and a gym with a full-length basketball court.

In a clearing south of the complex, dozens of middle school kids were engaged in activities, with a wilderness area at one end of the island, and an outdoor "challenge course" at the other.

This bustling community is The Thompson Island Outward Bound Educational Center. Since 1988, Outward Bound has owned and maintained the island. Each year they host overnight, days-long, even weeks-long visits from thousands of Boston Public Schools students. They engage in everything from outdoor challenges meant to help with team building and leadership skills, to field-based educational activities aimed at improving STEM skills.

And it takes a village to pull it all off. Scores of full-time employees do everything from landscaping to maintenance to cooking.

"I live in Mattapan," said cook Mark Jordan. "To get here I have to take two buses, a train, and a boat ... every day ... to and from."

But not everyone commutes. Among the staff are educators who live here on the island full-time. Two of those educators are Ward 1, Precinct 15's only active voters.

Kate Jamison is in her first year on the island, and her preparations to move there included ensuring she was registered to vote.

"I’m very engaged in the democratic process. It’s vitally important to me, and I knew I was going to be here, so I made it work," said Jamison.

Caroline McCall is old-hat, now in her fourth year on the island. She was the precinct’s lone voter in 2016.

"I remember when I went to go vote they were like, 'What’s your address?'" she explained of 2016. "And I remember being a little hesitant and nervous, and I was like, '0 Thompson Island.' And the lady was like, 'Great. Glad to have you.'"

The precinct doesn’t have its own polling location. And so, on election day, Jamison and McCall will work a full day on-island, hop on a 4:30 p.m. boat to the mainland, jump on the Silver Line, send to the Red Line, then walk 10 minutes to a shared polling center. And make no mistake, they say they are voting.

"One our values in Outward Bound is integrity," said McCall. "We ask our students to show and practice integrity in their action with each other and with themselves. And I think voting is asking our elected officials to have integrity for the populations they serve."

A lot will be said about voter turnout across the country on election night. But you can expect at least one tiny precinct in the city of Boston to have — among its active voters — 100 percent participation.