It is eight in the morning on the second-to-last day of August. Brazil is mired in an impeachment crisis that has roiled the country for nine months. In 29 hours, an unpopular president will be forced out, and the streets will erupt into protest over her replacement. It is one of the most intense days in the recent history of Brazilian politics, but eight candidates for mayor and vice-mayor of Rio de Janeiro have all taken the morning off from the campaign trail to accompany a biologist and Star Wars fanatic on a trip down a lagoon that smells of rotting eggs and sh-t.

Mario Moscatelli's battered aluminum boat floats atop a viscous, olive-green soup. Bubbles rise to the surface and make a lugubrious noise when they pop. The candidates, their campaign staffers, and a smattering of reporters watch the environmentalist from a larger, more stable barge. But the smell hits everyone at once. "Methane and hydrogen sulphide," Moscatelli will soon explain, a byproduct of decomposing sewage.

Moscatelli shows onlookers a sample of contaminated mud pulled up from the bottom of the lagoon | (Cleuci de Oliveira/Courtesy Narratively)

"Our city has the word 'river' in its name," he says. (Rio de Janeiro, translated literally, means River of January.) "And all of our rivers are dead."

Tijuca Lagoon is one of four lakes in the Jacarepagua lagoon system, which borders the increasingly irrelevant Olympic Park. In 2009, when Rio submitted a bid to host the games, it promised to dredge Jacarepagua Lagoon and turn its waters into a swimming destination. None of that ever happened. The city also pledged to build five sewage-treatment plants along the rivers that feed into the lagoon system, but only completed one, The Washington Post reported in July.

In August 2015, less than a year before the opening ceremony, about one ton of fish turned up dead in the lagoon in a single day. The majority of them were tilapia, according to Moscatelli, who says they "can probably survive in hell." The culprit, the State Environmental Department announced at the time, were strong winds that had whipped the toxic sludge at the bottom of the lagoon and overwhelmed the water with noxious gases — the same ones now giving off a pungent smell. In April, during a test event at the handball arena, athletes complained that the stench had wafted onto the court.

Of all the government's unmet environmental pledges in the run-up to the games, most controversial was the failure to decontaminate Guanabara Bay, where the sailing competitions took place. For months, the media focused on the filth found in the water: human waste; super-bacteria; enough furniture, appliances and car parts to stock a Midwestern city; dog carcasses; a corpse. Now the world's attention is gone, and Moscatelli is left to wonder whether the sanitation issues that plague Rio will ever be addressed at all.

Moscatelli singles out the state's water and waste management company, CEDAE, as having what he calls a "monopoly" over the sewage dumped in the Jacarepagua lagoon system. While the company supplies water throughout the state, an April investigation by newspaper O Globo found that it only collects sewage from 38.9 percent of its customers. In the same month, Brazil's federal police raided at least six of CEDAE's treatment plants as part of a year-long probe into suspicions that the company has been illegally dumping sewage across Rio's waterways and taxing citizens for water treatment that it never carried out.

An aerial shot of the Jacarepagua lagoon system, near the Olympic park. The water is bright green because of the cyanobacteria proliferation, due to pollution, in the lagoon system. Such bacteria can cause liver cancer, says Moscatelli. These proliferations happen every summer, according to him. | (Mario Moscatelli/Courtesy Narratively)

Trash litters the banks of the lagoon | (Cleuci de Oliveira/Courtesy Narratively)

"If we followed the letter of the law, we'd see plenty of Cedae chiefs arrested," Moscatelli says, pointing at the candidates. "Arrested. Because environmental criminals belong in prison."

The political candidates who showed up to Moscatelli's lagoon expedition include a human rights activist who inspired a character in Brazil's highest-grossing movie of all time, a right-wing lawyer running for vice mayor and the country's former minister for racial equality. All are more accustomed to delivering speeches than listening to them. That Moscatelli managed to corral these strange bedfellows onto a barge may be a testament to his reputation (legendary) or the dire case of water pollution in Rio (a public health emergency) or, more likely, the sheer relentlessness with which he pestered them on Facebook until they RSVPed.

Moscatelli speaks to political candidates and their staffers in Rio de Janeiro on August 30th | (Cleuci de Oliveira/Courtesy Narratively)

"It's what I always tell people: To be a cuckold is part of the game," Moscatelli says. "But to get cheated on and take it lying down? That's a choice."

Read the rest of this story at Narratively.

Narratively is a digital publication and creative studio focused on ordinary people with extraordinary stories.