The Gulag Archipelago, 1918-1956 is a nonfictional, partially autobiographical work by Aleksandr Solzhenitsyn examining the Soviet gulag system and detailing life in prison labor camps. The book interweaves historical analysis of the development of the system with an anecdotal journey of the process an average zek (gulag prisoner) might have experienced.

Solzhenitsyn begins by discussing the initial process of entry into the system: arrest. He notes that most targets did not resist and instead trusted that someone in the system would realize their mistake and free them as long as they complied with the process. Speaking of those in charge of arrests, Solzhenitsyn explains that Russian State Security was very intentional about where and how they arrested their targets. The way these arrests were viewed and interpreted by onlookers was an important consideration, as they were often used to instill fear in onlookers. 

Alternatively, arrests done in the middle of the night in apartment complexes could startle the entire building. Solzhenitsyn notes that in some cases, entire families were sent to the gulags, while in others, the arrest would only target the head of the household. The conduct and targeting of arrests depended on the class of the crime as justification and were based on highly variable context and interpretation. Therefore, public arrests were not only an intimidation tactic based on uncertainty but also a means of consolidating regime power. 

Solzhenitsyn transitions away from arresting procedures and begins to discuss search procedures. He highlights the incredible level of detail expected—including ripping out dental implants, digging up cesspools, and seizing mundane objects such as hay. The next step in the path of a zek is interrogation. Solzhenitsyn uses his own experiences to explain the brutality of this step. During his time in a gulag, he was subject to torture by sleep deprivation. However, Solzhenitsyn adds the caveat that his experiences were mild compared to the 31 official torture techniques used later in the gulag system. He provides a host of anecdotes in which the refusal to confess was viewed as a crime and met with capital punishment.

Following interrogation, zeks were imprisoned. Solzhenitsyn notes the comradery of zek cellmates. They often shared stories about former Russian traditions of visiting and cooking for prisoners and shared hopes of being granted appeals or amnesty. He also records terrible material conditions, often including a lack of food, bedding, and adequate clothing to protect zeks from the back-breaking physical labor and mental exhaustion from the complete isolation from the outside world.

Next, he discusses the trial and sentencing process. Initially, Russian State Security faced resistance and backlash during such trials due to their lack of rigorous evidence and the harsh punishments they sought. To avoid public anger, they transitioned to private tribunals, which allowed them to try zeks without civilian questioning or oversight. Prisoners were prevented from attending their trials, which streamlined the processing and sentencing of millions of people to the gulags. Solzhenitsyn notes that many prisoners continued to expect amnesty or an opportunity to appeal their sentence through this process, only to find that those arrested under article 58 were exempt from any such relief. Their appeals and petitions never went beyond the gulag officers whose decisions they sought to appeal.

Solzhenitsyn notes that Soviet Premier Vladimir Lenin implemented this system immediately following the October Revolution in 1918 rather than beginning under Joseph Stalin as many of Solzhenitsyn's contemporaries argued. He instead claims that Stalin inherited a vast system of concentration camps and merely intensified the transfer of undesirable populations into these camps. The work ends on a somber note, arguing that while the system ceased widespread use after Nikita Khrushchev succeeded Joseph Stalin, it remains intact and would be easy to revive. The sins of the Soviet past are neither buried nor inaccessible, a bleak reality Solzhenitsyn is careful to drive home.