At once a political thriller and human drama, "The Lives of Others" begins in East Berlin in 1984, five years before Glasnost and the fall of the Berlin Wall and ultimately takes us to 1991, in what is now the reunited Germany. "The Lives of Others" traces the gradual disillusionment of Captain Gerd Wiesler (Ulrich Muhe, best known for his lead roles in Michael Haneke's "Funny Games" and as Dr. Mengele in Costa-Gavras' "Amen"), a highly skilled officer who works for the Stasi, East Germany's all-powerful secret police. His mission is to spy on a celebrated writer and actress couple, Georg Dreyman (Sebastian Koch) and Christa-Maria Sieland (Martina Gedeck).
Five years before its downfall, the former East- German government (known as the GDR, German Democratic Republic) ensures its claim to power with a ruthless system of control and surveillance via the Stasi, a vast network of informers that at one time numbered 200,000 out of a population of 17 million. Their goal is to know everything about "the lives of others."
Devoted Stasi officer and expert interrogator Wiesler is given the job of collecting evidence against the famous playwright Georg Dreyman. The job begins after Lieutenant Colonel Anton Grubitz (Ulrich Tukur), a former classmate of Wiesler's who now heads the Culture Department at the State Security, invites Wiesler to accompany him to the premiere of the new play by Dreyman, also attended by Minister Bruno Hempf (Thomas Thieme). Minister Hempf tells Grubitz that he has doubts about the successful playwright's loyalty to the SED, the ruling Socialist Unity Party, and implies that he would approve of a full-scale surveillance operation. Grubitz, eager to boost his own political future, entrusts the monitoring, or "Operative Procedure," to Wiesler, who promises to oversee the case personally. Wiesler is also convinced that Dreyman cannot possibly be as loyal to the Party as has always been assumed.
While Dreyman is away from their home, his apartment is systematically bugged. A neighbor who notices the operation is forced to keep silent by a personal threat. Wiesler sets up his surveillance headquarters in the attic of Dreyman's apartment building, thus beginning Wiesler's cold and calculating observation of the lives of the playwright and his girlfriend.
At first Weisler's observations show that, unlike most of his artistic peers, Dreyman does not display any outwardly disdain for the GDR. Dreyman's position slowly changes however, as he discovers that Christa-Maria has been pressured into a sexual relationship with Minister Hempf. When his close friend, theater director Albert Jerska (Volkmar Kleinert) is driven to suicide after seven years of unofficial "blacklisting" by the government, Dreyman can no longer remain silent about the GDR. Now determined to alert the outside world about the conditions of life under the GDR, he begins a plot to place an article with the famous West German publication Der Spiegel, exposing the GDR's policy of covering up the high suicide rates under the regime.
Wiesler, who has been monitoring all of Dreyman's activities, finally has the proof he needs to destroy his subject and to serve the GDR by foiling Dreyman's plot. But Wiesler's unemotional façade is showing signs of erosion. While he observes the day-to-day life of Dreyman and Christa-Maria, he begins to be drawn into their world, which puts his own position as an impartial agent of the GDR into question. His immersion in "the lives of others," in love, literature and freethinking, also makes Wiesler acutely aware of the shortfalls of his own existence.
When the anti-GDR article is published, the regime is thoroughly embarrassed and Grubitz is ordered to discover the identity of the article's author. Dreyman is one of the prime suspects, but Grubitz cannot believe that the trustworthy Wiesler would have failed to discover the plot. At the same time, Hempf's discovery of Christa-Maria's drug addiction forces her to expose her lover as the author of the Der Spiegel article, but a search of Dreyman's apartment does not yield any incriminating evidence. Convinced that Weisler knows more than he is revealing, Grubitz summons him to interrogate Christa-Maria in order to find the one item linking Dreyman to the Der Spiegel article. Wiesler, who has known all along about the source of the article and purposely failed to disclose the information to his superiors, must now decide where his allegiances lie. If he does not extract the information from Christa-Maria, his life and his career as an elite Stasi officer will undoubtedly be over. If he succeeds, Dreyman's fate will be sealed.
In 1991, two years following the fall of the Berlin Wall, Dreyman is in for a rude awakening when he runs into ex-minister Hempf and learns that he had been the subject of a Stasi surveillance. Immediately afterward, he finds the cables and microphones secretly installed years earlier behind the wallpaper in his apartment. In disbelief, he sets out to research and discovers the different reality of his past, which not only has a profound impact on his life but also surprises him with shocking revelations.