The most terrifying parts of “The Handmaid’s Tale” are the flashbacks, to a time very much like ours.

Before the coup, Offred has freedom, a job, Uber. Then things start to change — little things. The government becomes more reactionary. One day, a coffee shop clerk, unprovoked, calls her and her best friend, Moira, “sluts.”

Something primal and angry is awakening. Some people are exhilarated: Finally, they can say what’s on their minds, without the P.C. thought police cracking down! The show is also attentive to how progressive men can back-burner the concerns of women. Offred’s husband, Luke, for instance, is convinced that the craziness is bound to blow over.

It doesn’t. An intermediate layer of flashbacks finds Offred, Moira and a class of future handmaids at a re-education center being indoctrinated, with homilies and a cattle prod, by Aunt Lydia. “This may not seem ordinary to you right now,” she tells them. “But after a time it will.”

The line is terrifying, because it rings so true. You may not believe that anyone, in real life, is actually Making America Gilead Again. But this urgent “Handmaid’s Tale” is not about prophecy. It’s about process, the way people will themselves to believe the abnormal is normal, until one day they look around and realize that these are the bad old days.