For those who believe history moves in a straight line, and what’s past is past, some signs can set you thinking. Like you’re being awakened to a bad dream—a strangely familiar one—and bits and pieces of memory flash by, brought back to life. Words that recall a time of great tumult—Khalistan, Sikh radicals, Bluestar, 1984 pogrom—are abuzz again. If your attention has been focused elsewhere, little pieces of news are recalling an epoch filled with thousands of unknown victims, marking out new stirrings full of old forebodings.