I picked up Until Proven Safe: The History and Future of Quarantine, by journalists Geoff Manaugh and Nicola Twilley, with a degree of dread. Who wants to remain, even intellectually, in that claustrophobic place in which we slunk and mouldered our way through 2020 and 2021?

But there's something that feels impossible, too, about leaving it behind, despite the call of shot girl summers and the advent of the UK's absurdly named "Freedom Day." Life appears increasingly normal for the vaccinated, but death and sickness continues to tear through the unvaccinated world. Which of the warring impulses — relief or fear, celebration or lingering grief — should we give in to? Should we be dancing, or mourning, or both? It's hard to imagine what closure might look like.

So there is something counterintuitively comforting in a deeply-considered book that contextualizes and justifies the seclusion and uncertainty of the past 18 months. Even if it felt chaotic and unprecedented to those of us who had not lived through it before, quarantine is in fact "one of humanity's oldest and most consistent responses to epidemic disease," the authors write.

Until Proven Safe is not a hastily assembled response to the events of the past year and a half, but the result of many years of research. That might sound freakishly prescient, but Manaugh and Twilley make the case that disease and the quarantines they inspire have in fact shaped much of the modern world, from international borders to passports to trade and agriculture. "Quarantine restrictions, we came to realize, lie at the root of most global institutions and frameworks, preserved like a fly in bureaucratic amber," they write.

Simply put, quarantine has always been an answer to the problem of doubt. "[T]here might be something dangerous inside you — something contagious — on the verge of breaking free," the authors write. "The space and time you need to see whether it will emerge is quarantine."

The earliest recorded formal quarantine was in 1377, when the city of Dubrovnik mandated that those arriving from plague hotspots must first spend a month in a designated quarantine outpost. Quarantine facilities spread across the Mediterranean as a way to slow the spread of bubonic plague, and we've lived with quarantine in various forms ever since.

Manaugh and Twilley visit an impressively broad array of quarantine projects, many of which would be incomprehensible to the residents of 14th century Dubrovnik. There is a section, for instance, devoted to the question of planetary quarantine, or how to ensure that we don't contaminate space or vice-versa. After the Apollo moon landing, for example, astronauts were held at the "Lunar Receiving Lab," in Harris County, Texas. "In the event of an actual alien contagion, officials later revealed, the plan was to bury everyone in the laboratory alive under a mountain of dirt and concrete," the authors write, "sacrificing astronauts and NASA scientists alike." (This turned out not to be necessary).

One of the book's most fascinating sections looks at how to quarantine something not only in space but in time. The authors describe the (equal parts absurd and wonderful) proposals for how to warn future generations away from nuclear containment sites while the material is still dangerous. Should there be a kind of nuclear priesthood, whose mission is to cultivate a sense of superstition and foreboding around the area? Should we breed cats that change color in the presence of radioactive material, so that their owners realize something strange is nearby? Display a copy of Edvard Munch's The Scream on the outside, to convey primal, speechless terror in case the denizens of the future can't read English? One report sponsored by the Department of Energy suggested carving, on a massive stone monument, warnings such as "This is not a place of honor...no highly esteemed deed is commemorated here...nothing valued is here."

There are consistent anxieties running through each of these very different quarantine projects — anxiety about individual liberty, about outsiders, about how to communicate danger convincingly, and about whether it is possible to have spiritual or artistic life in isolation. The authors write, for instance, that in medieval Split, a pulpit was attached to a tower overlooking the sea, "from which a priest could perform an open-air, distanced mass for sailors quarantined aboard their ships." There's a kind of wonderful, cross-century kinship there with the Detroit priest who anointed congregants with holy water using a squirt gun during the COVID-19 pandemic.

These little echoes and threads across the centuries are reminders that the next quarantine is a matter of when, not whether. But they also show how inexhaustibly and creatively people have tried to find ways to be together, even while apart. At one point, Manaugh and Twilley quote some lines carved on the walls of Angel Island Immigration Station, where Asian immigrants were often quarantined in the early 20th century before being allowed to enter California. "Over a hundred poems are on the walls....What can one sad person say to another?" wrote "Xu, from Xiangshan." But he still wanted to leave a mark — some form of company, perhaps, some reminder that other people had been there too.

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