Editor’s Note: The Atlantic is making vital coverage of the coronavirus available to all readers. Find the collection here. Last spring and summer, when a COVID-19 vaccine was only a glimmer of hope on the horizon, scientists warned in their careful way that vaccines might not live up to the public’s high expectations. The FDA said a vaccine needed to be just 50 percent effective.

“When you pray, do you get a response?” A terminally ill cancer patient named Amanda (played by Jennifer Ehle) poses this innocent-sounding but loaded question to her nurse, Maud (Morfydd Clark). Amanda knows that Maud is religious and says her nightly prayers, but Maud reveals that her devotion to God runs even deeper. “Sometimes he talks,” the nurse replies. “Most of the time it’s just like he’s physically in me, or around me.

On a warm September afternoon, on San Juan Island off the northwestern coast of Washington State, I boarded J2, a sleek black-and-white whale-watching vessel. The boat was named after a locally famous orca, or killer whale, affectionately known as “Granny.” Until her disappearance in 2016, Granny was the matriarch of J-pod, one of the three resident orca groups, or pods, that live in the surrounding Salish Sea.

Troy Hudson didn’t want to think about Mars. It was Christmas, he had taken some time off, and this planet had enough going on at the end of 2020. But Mars was difficult to escape, he told me. It twirled in a mobile of the solar system in his home. It sat right there on his skin, tattooed on his arm, below the elbow. Hudson had spent more than a decade working on a robot that was currently parked on the surface of Mars, and NASA was about to decide whether to give up on it.

I often think of fiction as fact’s partner in the pursuit of truth. At its best, the genre is capable of rendering the worlds we’re unable to imagine, and also of revealing the ones hidden around us. Last year, The Atlantic recommitted itself to publishing fiction with greater frequency.