The end of the world is pretty terrifying, no matter how it happens. In the upcoming Netflix series “The Rain,” the main culprit is a deadly downpour that wipes out most of Scandinavia’s population.

People outrunning killer weather isn’t entirely new in apocalypse stories (just ask Jake Gyllenhaal), but it looks like this show is more concerned with what happens years later, after two children who survived the initial attack venture back out into the world to find companions. Emerging from a bunker they’ve been locked in for half a decade, they eventually found people who had their own way of lasting through the killer precipitation.

After finding a small pack of other survivors, it’s clear that even though the streets and schools and supermarkets are deserted, the danger didn’t end when the deadly virus got swept away. There are guns and gangs and killer...