Joseph Purcell sits on a motel bed in [redaction] fingering his prayer beads as he enjoys watching a cartoon featuring numerous explosions.
The same morning, Will wakes up after having spent all night sleeping in a chair with a bat in his hand. He wipes the blood spot he noticed the night before off of his mantel.
Over breakfast, Spangler, James Wheeler, R.C. Gilbert, [redaction] , and [redaction] argue over the wisdom of proceeding with their "operation" given that Will is still alive and knows so much. "You left us all exposed!" R.C. screams at Spangler. Spangler tells the group that it's too late to stop things and that Will is under control.
Will arrives at Katherine's loft to warn her that she is in danger and must leave immediately. With Will's help, Katherine determines that Tom's note about continuing to celebrate their anniversary is a reference to their tradition of screening Meet Me in St. Louis every year. "Find that movie," says Will.
At API, Spangler announces to senior staffers that Kateb is about to attack and assigns Will and Grant to go to a temporary field office being set up in New Jersey where Purcell's friends and relatives will be questioned.
On Kale's instructions, Maggie visits Katherine and presents her with Will's business card, on which she's written "Not safe here" and "Please trust me." Katherine agrees to accompany Maggie.
In API's conference room, Miles spars with an FBI analyst who has orders to try to identify vulnerable population centers that Kateb might attack. "The target follows the tactic, not the other way around," protests Miles, who says that to determine where Kateb will strike they must first figure out why he has returned to the U.S.
In New Jersey, Purcell's relatives and friends - all of whom are estranged from him - provide few clues to his current mind-set. His stepsister reveals that after the 9/11 attacks, "Joey" joined a group that wanted to talk with Muslims to "get them to stop hatin' us."
At a safe house, Kale describes to Katherine the actions of the Roman senator Cato after Julius Caesar defied his government and crossed the Rubicon river with his army. Cato realized that Caesar would become Rome's dictator, and though he refused to surrender Cato killed himself "so that those he loved could make peace with Caesar."
"Tom killed himself to protect me," Katherine reflects.
As Kale departs, he orders Maggie not to open the door for anyone but him.
Spangler enters the conference room looking for Kale, but no one knows where he is. At Miles's request, Spangler referees the strategy dispute by calling the FBI analyst's boss and informing him that API's methodology is the approach that will be taken.
Back in New Jersey, Purcell's belligerent uncle snarls at his interviewers. Grant remarks that the command center seems "totally disorganized." Will suggests that they contemplate what motivated previous American jihadists.
Back in his motel room in [redaction] , Purcell pleasures himself while watching porn.
By phone, Miles informs Will that he has just received FBI intel revealing that Tanaz visited the United States multiple times. Will calls Maggie and asks her to run an errand for him, then speaks to Katherine about the movie, which she hasn't located yet. Will tells her to remain at the safe house for the time being.
In his office, Spangler receives an envelope from Atlas MacDowell containing a photo of Kale, Maggie, and Katherine together. Spangler's hands shake when he tries to light a cigarette.
Moments later, Kale arrives. "Forty years in the intelligence business," says Spangler. "I somehow thought I was past being surprised." Spangler waves off Kale's explanation of his earlier whereabouts and thanks him for "everything."
Maggie goes to Andys apartment under the pretense that she is there to look for a book that Will thinks he left in her bedroom. Asking to use the bathroom, she takes the opportunity to retrieve Will's research from where he hid it. "Are you sleeping with him too?" Andy asks Maggie as she leaves. Maggie replies no.
Will leaves New Jersey, and Grant stays to interview Purcell's ex-girlfriend Virginia, who describes "Joe" as "confused," though in an endearing way. "The Muslim stuff" broke them up, she says, adding that Joe "wanted someone to tell him that he was the special one, that he had a purpose."
In his motel room in [redaction] , Purcell writes letters to Virginia and [redaction] . Nearby sit carrying cases marked "FRAGILE."
Katherine leaves the safe house and goes to a storage space packed with boxes. In one, she finds a Meet Me in St. Louis DVD.
Miles spars with the FBI analyst, who hasn't read API's report about Kateb's pattern of striking at 4:20 p.m. Eastern time. Tanya backs up Miles.
Kale is furious when he sees Maggie is at API instead of with Katherine. Shaken, she hands Will his research.
Purcell loads the cases, which hold explosives and a detonator, onto a boat that he steers out of the harbor and into open waters.
At API, Will kicks everyone but Miles out of the conference room so the two can cross-check Tanaz's travel records. After they do, Will calls Kale.
"Bloom and Tanaz," says Will, "Kateb, the crosswords, it's all connected."
Will asks Kale about the "Houston problem" mentioned in David Hadas's white paper, noting that Bloom came from Houston every time he saw Tanaz. Kale explains that the paper analyzed Houston's pivotal position in the U.S. oil-supply system and how a tanker sinking in Galveston Bay would have a domino effect that would cripple the nation for months.
"That's where Kateb is headed," says Will.
Maggie rushes in and tells Will to turn on the television. A news reporter describes the attack on an American tanker in Galveston Bay. Smoke billows into the sky as oil spills into the bay.
Spangler's assistant notifies him that the CIA, NSA, and Pentagon are calling. "It's fine. We can wait a few minutes," he responds.
Will returns to his apartment after work. He touches the mantel where the blood stain was, then falls back and trembles.