Police states spread complicity by forcing citizens into immoral roles. With "The Day Will Pass Away," readers get a remarkable opportunity to peek into the 1930s diary of one such citizen — Ivan Chistyakov, a guard in the Soviet gulag.

Under Communist rule during the 20th century, Russia herded millions of residents into labor camps without trial. Many were sent thousands of miles to vast infrastructure projects in an attempt to shock-industrialize the nation. As purges under Stalin began and executions swept the country, Chistyakov found himself in command of an armed platoon on the Baikal-Amur Mainline railway, an eastern outpost of the camp system.

Already expelled from the party, Chistyakov is dismayed by his assignment. His duties entail walking up to 30 miles a day in subzero weather to hunt down escapees and return them to camp. He simultaneously sympathizes with and condemns the zeks, prisoners who are forced to build the railroad under his disinterested watch.

Chistyakov is no dissident plotting to smash the state. He notes how inmates have the chance to win rewards for meeting or exceeding production quotas, and he longs for the guards to be told that their contribution to the railway will also be remembered. According to his own words, what the guards as a group have done includes shooting prisoners, beating them with rifle butts and putting them in brutal solitary confinement.

As with many diaries, Chistyakov's account is most sympathetic to its author. At least the prisoners, he feels, receive a fixed sentence, while he has no idea when or if the government might release him from service.

He repeatedly tries to resign and contemplates committing an offense so as to join the zeks. In September 1936 he writes, "I am almost an animal."

"The Day Will Pass Away" captures the process by which a whole society becomes a prison and each camp evolves its own society. With increasing frequency, Chistyakov contemplates suicide. His despair rises from a premonition that for himself, there will be no escape.

The translation by Arch Tait is adroit and haunting, without adding excess literary polish to Chistyakov's journal. An introduction by Irina Shcherbakova of the human rights organization Memorial provides historical context for readers unfamiliar with the gulag.

Lacking the overt arc of a plotted narrative, this diary nonetheless conveys the increasing hopelessness of life at a forced-labor camp. Through notebooks unearthed long after the era in which they were written, Chistyakov provides a singular account from a category of gulag witnesses whose voices have rarely been heard — those who were neither the main victims nor the instigators of a brutal system but its unwilling enforcers, doomed to bit parts in both roles.

Andrea Pitzer is the author of forthcoming "One Long Night: A Global History of Concentration Camps," and of "The Secret History of Vladimir Nabokov."

The Day Will Pass Away
By: Ivan Chistyakov, translated from the Russian by Arch Tait.
Publisher: Pegasus, 249 pages, $25.95.