Three months prior to The Cicada Protocol, Bentley was captured by Petra Andropov, a KGB agent. He was tortured, given hallucinogenic drug cocktails, and run through other forms of behavior-modification protocol over the course of nine months to become a cicada, a sleeper agent who would follow certain prescripted commands when "awakened", or activated. During activation, Bentley himself thought he was in a jungle war zone, and rapidly shot and killed several people who he thought were enemy soldiers, who in actuality were prisoners that Petra directed him to kill.
While being ministered to by Dr. Meisner, who Bentley was originally sent as a CIA agent to kill, Bentley turned on him and killed him with his own glasses. He then fought his way out of the facility he was being programmed in, reached an American safe house, and called for help. He dodged the pursuing agents, stole one of their cars, and escaped.
Arriving CIA station in Berlin, Bentley thought he was safe among his American comrades. Unfortunately, station chief Dennis Kohler thought that he might have been deliberately released due to his lack of memory of the past 9 months and his description of feeling "whole" when his torturers stripped away his memories and personality. Unwilling to undergo further psych evaluation or to be thought a traitor, Bentley fought his way out of the facility and escaped once more, vowing prove his loyalty somehow.
Returning to the KGB facility in Berlin, Bentley discovered that his tormenters had long since vacated the area. He interrogated a cleaning lady in another language, and managed to find Petra's watch, but otherwise came up empty handed. With no other options, he called Frank Ferguson and arranged a meeting to help him prove his good intentions. At the meeting, Ferguson revealed the deaths of Dan Ellender, Kurt Jenkins, and Kay Newman, the agents who Bentley shot when he was last under soviet control, which Bentley tearfully admits to. Ferguson then brings in Dennis Kohler; Ferguson set Bentley up.
However, Kohler had other ideas. He instead shot Ferguson, setting it up to look like Bentley himself killed Ferguson, and tasked Bentley with bringing Petra in for interrogation. Kohler was so impressed by Bentley's brainwashing that he wanted her to help the Americans figure out how to do it themselves, and offered to wipe Bentley's slate clean if he can help pull it off. Bentley is told to search in Budapest, where he was last seen but had no memory of ever visiting.
Bentley looked over the files of Don Matheson, an agent who vanished trying to rescue him, and the other CIA agents who he personally killed while traveling to Budapest. On arrival, he went to a bar where he was last seen by the CIA, only for the bartender Miklos to immediately, fearfully recognize him. He refused to speak however, so Bentley stayed in the bar until everyone else mysteriously vanished, at which point Miklos pulled a gun on Bentley.
Bentley disarmed Miklos and fought off several locals out for "revenge" for abuses Bentley doesn't remember committing, using gas and a broken light bulb to create an explosion. The leader claimed that Bentley threatened them for "months", and threatened that they knew where he lived, so Bentley got the address from him. The address turned out to be a hotel where the KGB previously stayed, so the innkeeper Karoli gave Bentley his old room key.
There he found his name written on a closet wall, but began to cry as he could not remember writing it. He noticed a see-through mirror, and discovered a camera on the other side, leading to a secret set of rooms. Inside were recordings of Bentley torturing Don Matheson for information on Ellender, Jenkins, and Newman's locations, with Petra being depicted kissing Bentley passionately as well. Karoli then arrived, and revealed under duress that Bentley tortured local criminals and killed them in his inn.
Bentley then went to a bar and was approached by a local named Katya, who plied him with LSD to help him remember his past.
As the drugs took effect, Bentley began to remember his time in Krakow just after gaining intelligence on what the soviets were doing in the Cicada program. He and Ferguson had fled from soviet soldiers, and Bentley drew them away so that Ferguson could escape. Although he didn't intend to be taken alive, Petra knocked him out from behind and captured him.
In captivity the soviets tortured Bentley in a myriad of ways, including waterboarding, light torture, electroshock therapy, sonic torture, physical abuse, and psychological abuse in the form of Petra beginning a relationship with him during the torture. However, despite the extremity of his ordeal, Bentley had to relent in at least some fashion in order for the drug intake to take hold, and when he did not, Dr. Meisner recommended him for termination. Just before termination, Bentley began to hallucinate and to hear voices calling his name after the extreme torment he had suffered.
Eventually Petra arrived and gave him food, at which point he finally cracked and revealed his name to Petra; he relented. They then began to ply him with a variety of drugs and to train him in combat, becoming a loyal soldier for the soviets. He performed so well that they sent him to Budapest early to learn how to torture people, eventually being given Don Matheson himself, one of Bentley's comrades, to torture. Apparently Bentley called for exfiltration from his CIA comrades, but when they arrived to save him they were captured by a KGB ambush. Bentley then proceeded to torture Matheson, just as the recordings depicted.
Bentley was later sent to Berlin to finish his training, and here his conditioning began to break down. Be confided in Petra that he didn't feel in control of himself around her, that he began to question who he was. Bentley blamed the training, but Petra insisted that it was their relationship that made him feel that way. When Petra brought him before Meisner to kill his former comrades, they called out his name, which partially jogged his memory. He insisted that he couldn't kill them, and screamed as he was taken away by KGB guards.
His scream, just before he was brought to kill his comrades as shown in The Cicada Protocol, turned into a real scream back in the bar where he took LSD. He has finally finished remembering everything that was done to him by the KGB in the past, but at that very moment the bar was raided by the KGB in the present. Fighting off KGB agents attempting to recapture him, Bentley tried to flee, but drugged as he was on LSD he could not escape, and was recaptured by Petra.
Bentley awakened in a warehouse watched over by Petra. He claimed to have remembered everything Petra did to him, and Petra asked if he remembered their relationship. She claimed that she started to doubt the program and fell in love with Bentley, at that moment even shot one of her fellow comrades when he arrived to take Bentley. Bentley still wanted nothing to do with her, disregarding her offer to run away together in favor of freeing Matheson, but she insisted that he'd never find Matheson without her, and so they fought their way out of the warehouse together.
Petra took Bentley to a safe house in a theater in Budapest, but Bentley still couldn't bring himself to trust her, and so left without her to get some air. While out and about he notices Wilson, Matheson's CIA partner, who promptly runs after Bentley to attack him. Bentley tries to reason with Wilson, saying that Petra would help bring Matheson home, but he wouldn't believe Bentley and forced Bentley to shoot him dead. As he died, Wilson put a tracking device on Bentley, which Bentley didn't notice.
When Bentley returned to Petra, he knew that his own people would want him dead for killing a CIA officer. He prepared to shoot himself, but Petra stopped him by mentioning that Meisner was still alive, and had not in fact been killed by Bentley in The Cicada Protocol. She promised to help him find Meisner and his remaining CIA comrades, so he allowed her to take his gun away. In the heat of his emotion and confusion, he finally gave in and kissed Petra, and they had sex.
Petra arranged a meeting with Yuri Leniov to report that Bentley had been "captured", when in reality Bentley planned to fake it in order to be reintroduced to Meisner. Petra feared that she would never see Russia, or her favorite Lake Baikal, ever again, so Bentley offered to take her home with him to Hocking Hills, Ohio. She accepted, and Bentley returned her watch to her.
At the meeting with Yuri, Bentley pretended to be servile, even taking punches to the face with equanimity. Yuri then has Bentley taken to Meisner's new lab in Romania, where Meisner drugs Bentley and has him sent into a cell with Matheson. Bentley assured Matheson that they'll escape, but Matheson had already been turned into a cicada, and immediately reported Bentley to the guards. The guards beat Bentley and locked him in a single room with Matheson, and although Bentley tried to reason with Matheson, he was too far into the training to recognize Bentley.
Meisner arrived later and left both men a single disassembled gun and a bullet, telling them to kill each other to decide who who was the strongest. Matheson assembled the gun but Bentley stole the bullet, and managed to take the gun as well. Bentley urged Matheson to remember Andrea, his wife, and Russel and Melanie, his children. He then shot the wall right beside Matheson's head, at which point Matheson finally began to remember his past life.
With the memory of his wife urging him to come home safe, Matheson decided to work with Bentley to escape. They disarmed the guards who came for them and fought their way out of the complex together, stopping to take one of the last two prisoners, with the other refusing to leave because of a "woman with red hair" who would always come back for him if he stayed put. On the way out they encounter Meisner, who taunted Bentley, saying their escape was all part of the plan and that he and Matheson could never truly be fixed. Meisner ordered Bentley to return to America as a "hero" to complete his mission, and claimed that his own death was also part of the plan, at which point Matheson shot and killed him. Matheson and Bentley then fled the facility.
Bentley returned to the CIA with Matheson to a warm welcome, with Dennis Kohler calling him a hero and assuring him that the director himself wants to personally thank Bentley. However, Bentley wasn’t comfortable with Kohler murdering his friend Ferguson, and sworn to take him down, but Kohler was unconcerned and brushed it off as a necessity of war. Bentley tried to leave, but Kohler managed to convince him to stay by bringing up the fact that Petra was now in custody.
At their meeting, Petra was heartbroken that Bentley betrayed her, claiming to have left everything for Bentley. Bentley was unmoved however, because of the many other Americans she had tortured. In a rage, Petra attacked him, but when he left her cell he found that she had slipped him a note; "Remember Hocking Hills".
Years in the future, an old and wizened Petra Andropov visited an older Bentley in his home.