St. George is digging for a book in her backyard, accompanied by her partner, who suffers from dementia. He fails to recognize her, but St. George convinces him to let her in. When Kate briefly recognizes her, she gets angry when she sees the book that St. George has dug up. After Kate leaves, St. George writes Hale's name in the book.
In the present day, Hale is trying to brush up on his gun-loading skills, while Cobb prepares for a briefing. He receives a call from someone he hired to investigate Hale, who has found something on him.
Later, Hale and Michele go on another date to keep up the charade. However, Hale goes off-script and asks where Michelle goes to feel centered. She responds that she goes to the cemetery. As they get on the train, Hale experiences another headache as they approach the non-signal area. When the train stops there, Michelle admits that she has orders to kill him if things go south.
At the office, St. George orders Moira to use the hack to discover their enemy's allegiance. Moira summons Hale and orders him to join Cobb's operation, Poseidon, immediately. Cobb is upset and asks if it's necessary. Moira claims that there's an overlap between Claymore and Poseidon.
At the secure briefing, Hale questions why Moira is sacrificing the Poseidon mission, even though he knows the risks involved. Moira explains that they need to keep the ruse going because if the enemy receives no real information, they will become suspicious, kill Hale, and then flee. Moira argues that sacrifices must be made for the greater good.
Parker warns Moira that the mission will bring Hale a lot of internal turmoil and that he might bail under pressure. Instead of listening, Moira orders her to figure out a way to get Hale in line with the mission.
Meanwhile, Cobb and Amin update Hale on their mission, focusing their attention on a rising Slovakian politician named Hugo Klovach. Klovach is determined to save his country from an oppressive regime, and his financial backer, Ilana Leximan, has reached out to the US for assistance. Poseidon is tasked with secretly protecting Klovach as he returns to Slovakia for the presidential election, with the CIA team's help.
Cobb and his team have already embedded one of their operatives within the CIA team. However, the enemy is listening in on the briefing through Hale's device. After the briefing, Hale takes a long walk, grappling with feelings of guilt. He spends the next few days honing his gun-loading techniques, while Cobb questions Marlowe's intentions behind clearing Hale for the Poseidon mission.
Cobb is convinced that Hale is compromised and has circumstantial evidence to support his claim. Marlowe warns him against pursuing anyone in Claymore, however. Later, Cobb meets with Schiff and conveys his concerns. Schiff asks him to temporarily drop the issue, warning him that it might ruin his reputation if he continues investigating Hale.
At the office, Parker helps Michelle get ready for another date. She encourages her to earn Hale's trust so they can manage him more effectively. Michelle asks how Parker is handling the fact that they are about to get Klovach killed. This is when the weight of what is about to happen fully dawns on Parker.
Simultaneously, Frances shows Marlowe and Moira that Hale's signal is bouncing in different directions. She believes that Hale has a modified version of the Cassandra RU-258 signal and is working on narrowing down the signal paths. After Frances leaves, Marlowe updates Moira that Hale's family and friends are clean, but she's not ready to clear Rachel yet. She also explains how she handled Cobb's concerns.
The scene cuts to Remy entering Rachel's office under the guise of a cleaner and putting spyware on her laptop. She finds him inside her office but doesn't think too much of it. Elsewhere, Hale, Victor, and his parents attend a parade for military soldiers. While there, Hale meets a man grieving over his son who died in combat. The man proudly discusses his son's meaningful death and thanks Hale for his service. The man's impassioned speech gives Hale a new perspective on his Poseidon mission. As it turns out, Parker orchestrated the meeting to align Hale with the mission.
A few hours later, Cobb gets information that Klovach's team has switched routes. He asks the analyst to ignore the information, citing that the source is unreliable. However, Ellie overhears the conversation and briefs Moira. They decide to use Hale to get the new information from Ilana. Parker argues that sending Hale on a fieldwork mission will make him feel trusted.
Hale willingly volunteers for the fieldwork and successfully gets close to Ilana at a fundraising event. He clones her phone and gets the new route details for Klovach's arrival. The team also relies on Clarissa to determine the exact location of the safe house listed on the new route. Parker intentionally makes Ellie give Hale, Cobb, and Amin the new information simultaneously while they are all together.
Schiff gets the new route once Hale checks the document. Thereafter, all agents on the case head to the watch room to observe Klovach's arrival. Cobb asks about the new source, but no one gives him a definite answer.
Unfortunately, Klovach arrives with his family, and all of them are tragically lost. The mood in the watch room instantly plunges into somberness. Cobb is consumed by self-blame, while Hale and Parker are overwhelmed by a sea of guilt.
Later, Moira confronts Cobb for attempting to conceal the new information. Cobb questions why no one within the operation undergoes internal review following the incident. Moira lies, claiming they were monitoring for a potential mole within the CIA. He places the blame squarely on rogue CIA operatives under investigation. He also tries to persuade Cobb that Hale couldn't have sent the new information since they were all together in a secure room.
Meanwhile, Victor reaches out to Schiff to seek assistance for Hale. He expresses his concern that Hale is too naive and loyal, fearing he might be eliminated by the Orphanage. Victor knows that Hale is hiding something and wants Cobb to investigate it. However, Schiff declines, stating it would be improper for him to act since he works for the National Intelligence Office.
On the other hand, Michelle invites Hale to a church. She confesses that she lied about going to cemeteries to find her center. Instead, she goes to churches for that purpose. She leads him to the church basement, where there is no signal.
There, they discuss the cost of the mission. Michelle comforts him and reveals that she is supposed to report back everything he says. She promises to report only what he asks her to and advises him to find someone trustworthy to confide in.
Hale reveals that he feels guilty but believes the end justifies the means. Michelle reports that although Hale is conflicted, he trusts her and is on board with the mission.
Back at the office, St. George and Moira realize they are hunting a lone wolf with no loyalty who sells the information to the highest bidder. They also narrow down that the enemy might be processing the hack from somewhere in Southern Europe and is highly connected.
Before leaving the office, St. George gives Parker a notebook and asks her to write down the things she can't carry and bury them. She understands that Parker is struggling with the death of Klovach and his family.
The episode ends with Schiff talking to someone about Hale. They wonder when he will realize he has been compromised. They know that he has been cleared but want to find someone close to Hale to use as leverage in case things go south.
