After last week’s harrowing episode, the penultimate chapter of the season is more straightforward. Still, it marks a decisive turning point in Downey’s journey.

He is the first to reach the island where Dinah is being held. The British government agents assigned to the mission are frustrated with what they see as a “babysitting” job: the female agent stays with the girl while the men go off to kick a ball around to pass the time. Downey takes both of them down with precise shots, but for a moment there is uncertainty, since Amos is already on his trail — and for a few seconds we are left unsure which of them actually killed the guards.

The female agent runs with Dinah, convinced they will both be killed, but the girl recognizes her uncle and runs straight into his arms. We barely breathe, knowing that the real danger is only a few steps away.

In Oxford, Zoe’s mother-in-law calls Detective Varna to report that Zoe has disappeared and says she wants to hand over the envelope containing the crucial evidence Zoe had left in her care. Where is Zoe? We know the answer: at sea, with Sarah, trying to reach an island that does not exist on any map.

Their crossing is rough as the violent waves leave Zoe desperately seasick, and Sarah cannot navigate without a clear direction. The boat’s captain remains locked in the cabin, and the two women refuse to release him. Everything suggests disaster is inevitable. When the fuel runs out, they have no choice but to turn to the captain for help.

Downey takes another dose of his medication (which is running out) and is clearly in bad shape. His tenderness toward Dinah is deeply moving precisely because we know there is no future for him. Amos, who reaches the island with ease by tracking Dinah through the locator hidden in her stuffed toy, is already on solid ground, calm, methodical, advancing as the man of action he is.

With no alternative but to avoid being left adrift, Sarah and Zoe release the captain. He uses the extra fuel to refill the tank and explains that the “disappeared” island was seized by the British to establish a military post. He refuses to go near it for that reason — and because of his hatred of the English. Sarah then tells him the truth: the base, supposedly abandoned, is being used in a covert operation backed by the British government. When he realizes this means acting against the English, the captain agrees to help. He changes course. Without him, the two women would never reach their destination.

Amos reaches the base and is spotted by Downey through the security cameras. The chase that follows is excruciating, as it must be. The former soldier tries to hide Dinah before facing Amos.

Meanwhile, Zoe talks to Sarah about Joe, still shattered by the death of her husband, who became entangled with the restorer and was consumed by the conspiracy. Despite the marital crisis we witnessed at the beginning of the season, Zoe confesses that the many years they shared now feel painfully short without him. Then she quotes the poem by Philip Markin that gives the episode — and the series — its title, and that was one of Joe’s favorites:

“When the lights come on at four, at the end of yet another year?
Give me your arm, old Frog, and walk me down Cemetery Road.”

No one delivers poetry with the dramatic precision of Emma Thompson. Zoe tells Sarah that she reminds her of Joe: someone obsessive, always chasing something beyond his own abilities. Sarah replies that if Zoe wants to cry and mourn, she will never tell a soul. But Zoe’s grief is of another kind: “I want to hurt someone,” she confesses.

Varna now holds the falsified autopsy reports of the soldiers and appears ready to contact the Secretary of State. This conspiracy is likely to claim even more lives. C is summoned once again. The Secretary is already aware of the allegations and questions him about Dr. Wright. When C refuses to be truthful, she warns him that she will investigate on her own.

Upon reaching the island, Zoe and Sarah spot Amos’s boat on the beach. The captain leaves them there and sails away. There is no turning back. The two women head alone toward the military installations. Downey takes Dinah and the agent along a different route around the base. Everyone is finally in the same place.

And because this is a series, while Amos is still some distance away, Sarah and Zoe immediately arrive at the exact spot where Downey is hiding with Dinah. At last, Sarah finds the girl she has been searching for. The problem is that this reunion distracts everyone just as Amos closes in. Downey has only a pistol and very little ammunition; Amos has enough firepower for ten men. He opens fire. Dinah panics and runs toward Downey. The agent guarding her is the first to fall.

Downey explains that they must all run — otherwise Amos will kill them all. Since he is the true target of the assassin, he will act as the decoy. The women must reach the boat on the beach and escape. It is not a good plan, but it is the only one they have.

The tension becomes unbearable as Amos heads straight for their hiding place. Downey, having already taken his final dose of medication, manages to draw him away. The sequence is agonizing because we know how precise Amos is. He gets his revenge: Downey runs out of bullets and is killed. There is a cruel sense of relief in knowing Downey will no longer suffer — but it is devastating to watch Amos claim his victory. The villain even declares that he will kill Dinah and Sarah next, because he wants Downey to know how it feels to lose those he loves.

Amos returns to the base before the women manage to escape. Now it is Zoe who becomes the decoy. She arranges to meet Sarah at the boat and runs in the opposite direction, with Amos close behind. He nearly hits her several times, but plot armor intervenes. Sarah reaches the ship and turns back to rescue Zoe, making herself an easy target. Zoe realizes the impossible choice before her: if she runs, she becomes the target again; if she stays, Sarah and Dinah will die.

On the mined beach, Amos’s gunshots trigger the explosives, and we are left with Zoe’s apparent death caught in our throats. Sarah escapes in tears. Since there is still one episode left, we know this story is not over. At least we see that the Scottish captain is still nearby in his boat, watching everything unfold.

Amos understands that two loose ends remain, and killing Dinah is part of his revenge. The danger is still absolutely imminent.