The disappearance of Malaysia Airlines Flight 370 in March 2014 set off a worldwide search for the missing plane. How could a flight carrying 239 people just go missing? The mystery dominated news cycles for months. (In July 2015, a piece of the plane’s wing was found on an island in the Indian Ocean.)

But just three months after Flight 370 went down, another group of passengers went missing — 243 men, women, and children. The passengers were refugees, mostly from the severely repressive African country of Eritrea, fleeing the country in the hopes of reaching Italy. The boat they took from Libya disappeared in the middle of the Mediterranean Sea. This time, nobody noticed, except for the families of those missing.

Bobbie Johnson, a senior editor at Medium and cofounder of the Medium publication Matter, had been thinking for a while about the migration crisis and feeling powerless.

“As a European, I have been watching the refugee crisis and wondering how people can really understand what’s going on and make a tangible difference,” Johnson told me. “Finding out what happened here seems to be one way of doing that.”

"243 people disappeared. Young people. Women. Children…No one cares about it." Stay tuned for #GhostBoat on 10/7. pic.twitter.com/wU9uIOYX6m

— Matter (@ReadMatter) October 5, 2015

On Tuesday night, Medium launched Ghost Boat, a new series that aims to find out what happened to the boat and its passengers. Readers will be included in the investigative process. As Johnson wrote in the post introducing the series:

It is incredibly unusual for a boat to go missing without leaving a trace. There are hundreds of thousands of people traveling this route looking for peace and safety in Europe, but whatever happens — sinking boats, death, double-crossing smugglers — there is always evidence.

But there are clues about the Ghost Boat.

Odd phone calls, messages that can’t be traced, rumors, hints. We want to investigate them, with your help.

Over the next couple of months, Medium will run weekly posts exploring and following the case. The lead reporter, Eric Reidy, is an American journalist based in Tunisia. He’s working with Meron Estefanos, a Swedish-Eritrean journalist and human rights activist who publishes the radio show Voices of Eritrean Refugees.

The first “episode” is here. For at least eight weeks, Medium will run feature-length Ghost Boat stories along with running commentary of evidence and updates.

Medium has been experimenting with serialized storytelling for awhile, and the “impossible-to-ignore” Serial showed “a pathway of sorts,” Johnson said. But “I don’t think anybody has really cracked that nut in terms of text-driven episodic storytelling.”

In this case, form followed function, and the idea of telling Ghost Boat in a serial fashion made sense with the information that the team had. “If you put the structure before the story, you really run the risk of sucking all the life out of it,” Johnson said.

The project will pull in information from sources including the passengers’ families, “geolocated messages, shipping records, refugee camp data, satellite photography, [and] social media information.” All of the data will be made public via Medium’s site.

To help handle and verify the information, Medium partnered with First Draft, a “coalition” that seeks to verify user-generated content for use in reporting (and is backed by Google News Lab). Meedan, a First Draft member, will support the product’s translation needs and on-the-ground investigation, and will provide fact-checking software and mapping tools.

Al Jazeera’s AJ+ will promote the investigation with animated videos that set up the story and ask viewers to join the hunt for the missing people.

“The idea that a boat could go missing or sink in 2014 and not be on the radar of any authorities, with no bodies recovered, is pretty strange,” Eric Reidy told me. The team’s investigation centers around three threads. One is that the boat sank; in that case, forensic evidence might turn up, or satellite imaging could help. Another thread to explore centers around a series of phone calls that took place between some passengers’ family members and a phone number in Tunisia. A third possibility is that the passengers ended up back in Libya and are imprisoned there.

Reidy is in close contact with a number of the passengers’ family members. “One of the questions they always ask me is, ‘Do you think that there’s hope?'” he said. “It’s a difficult question to answer. I say to them that I’m not sure if there’s hope, but I know that nobody has done a proper investigation into this. We’re going to try to do a proper investigation, to see if there is reason to be hopeful.”