YEKATERINBURG, Russia — On the outskirts of this burly industrial center, off a road like any other, on a nowhere scrap of land — here unfolded the final act of one of the last century’s most momentous events.

A short way through a clearing, toward a cluster of birch trees, the killers deposited their victims’ bodies, which had been mutilated, burned and doused with acid to mask their origins. It would be 73 more years, in 1991, before the remains would be reclaimed and the announcement would ring out: the grave of the last Russian czar, Nicholas II, and his family had been found.

But the story does not end there.

Eleven people were said to have been killed that day in July 1918 on Lenin’s orders. Just nine sets of remains were dug up here and then authenticated using DNA. The remains of the czar’s son, Aleksei, and one daughter, whose identity is still not absolutely clear, were missing. Did their bones lie elsewhere, or could it actually be that they had escaped execution, as rumor had it for so long?

Only in the past few months have these questions dating from the Russian revolution apparently been resolved here, and only by a group of amateur sleuths who spent their weekends plumbing the case.