Schofield and Blake approach the front line and go into the trenches to find that the Germans have actually retreated. Schofield pours water on his hand and wraps it, as Blake jokes that he will be "wanking in no time." They deduce that the Germans have not been gone for long. They search the trenches, guns up, and find underground barracks.
Inside, they see a number of unoccupied bunkbeds, before Schofield locates a long passageway that will be their way through. As Blake tests the springs on a bed, he sees a rat nearby hanging from a bag. The rat climbs up on another bag, when suddenly, Schofield sees trip wire on the ground, suggesting that there is some kind of trap set up. As a rat drags one of the bags towards the trip wire, Schofield tries to stop it, but it sets off an explosion. Schofield gets crushed by some stones, but Blake manages to pull him out and stand him up, as he coughs. They narrowly escape the collapsing barracks. Outside, they climb a nearby hill and look out over a wide field, as Schofield pours water in his eyes to get the dust out. "Why in God's name did you have to choose me?" Schofield asks, annoyed to have been invited along on the mission by Blake.
Blake asks Schofield if he wants to go back, and Schofield tells him to fire the flare letting the men know they made it to the other side. They continue on, noting that the Germans destroyed all their own guns and trenches when they left. They talk about one of the soldiers, Wilko, whose girlfriend, a hairdresser, sent him some hair oil. Not wanting to take the hair oil with him, he slathered it all over his hair, and went to sleep, only to wake up and discover a rat sitting on his shoulder. The rat then bit his ear off.
The men see British airplanes flying above, heading back to the base. Schofield suggests that Blake will surely get a medal for saving him. Schofield tells Blake that he swapped his own medal with a Frenchman for a bottle of wine. "You should've given it to your family. Men have died for that!" Blake protests, but Schofield insists that the medal was just "a bit of bloody tin." Schofield confesses to Blake that he hated going home on leave, when he knew he could not stay there with his family, nearly crying in the process.
They arrive at a small farmhouse in a large field, where the Germans have chopped down all the cherry trees. Blake talks about the different kinds of cherry trees, because his mother has an orchard at home. He talks about how he and his brother, Joe, usually pick the cherries in the summer. They think the farmhouse is abandoned and go towards it tentatively. They find the house completely abandoned, and Schofield says he does not like it there. Finding a pail of milk, he pours some of it into his canteen, as a dogfight takes place between some planes in the sky nearby. The British planes successfully take down a German one, and the German plane crashes into the shed right next to the men.
They pull the pilot out of the burning plane, and as Schofield goes to collect some water, the pilot stabs Blake. After shooting the pilot, Schofield runs to Blake who is bleeding profusely. Schofield wants to bring him to an aid post, but Blake cannot walk and is bleeding heavily.
The entire plot of the film is centered around Schofield and Blake's need to cross dangerous enemy territory in order to save another British battalion. Two young men who have not had any responsibility before in the army suddenly find themselves tasked with an essential mission behind enemy lines. The premise has high stakes and a great deal of unknowns, which heightens the drama of the film and aligns the viewer with the characters. We want to see Blake and Schofield succeed, not only because we know that the fate of the British army is on their shoulders, but because they are unlikely heroes, relatable protagonists for whom it is easy to root.
There are ominous obstacles around every corner. In the German barracks, the men encounter a giant rat that sets off a booby-trap explosion. Just when it had seemed that they were alright exploring the German trenches in relative safety, there is a trap waiting for them that threatens their lives. Such is the structure of the film, that every moment matters seem relatively safe, something as simple or unassuming as a rat dragging a bag across the floor threatens to unravel it all.
In the wake of this difficulty, Schofield suffers a crisis of morale, and blames their sorry fate on Blake. After getting the remaining dust out of his eyes from the explosion, he rails at Blake, "Why in God's name did you have to choose me?" He resents having been asked to go on a mission that he feels they are unequipped to go on, and takes out his fear on his friend. The hopelessness of their mission is weighing on Schofield and he worries that it is all in vain, and he ought not to have gone on it at all. Soon enough, Blake makes his amends, however, and they continue on.
In between more action-packed sequences, there are moments of stillness and even levity. After their little tiff, the two men wander through a small forest and Blake tells a (darkly) funny story of a fellow soldier who got his ear bitten off by a rat while wearing an excess of hair oil. They laugh at the story and enjoy the pleasure of one another's company, even as they continue trudging towards their uncertain and dangerous future. Given the nature of the narrative, the viewer can tell that these moments of lightness are few and far between, stolen moments of joy and connection in the midst of a hellish war.
The hell of war is not far behind, as it turns out. After they investigate the farmhouse, a German plane crashes nearby, and the two men help the injured German pilot out of the cockpit. Even though the men try and help the German, exhibiting human kindness across the barriers of military antagonism, the German ends up stabbing Blake in the stomach. Schofield jumps into action, trying to help Blake to recover enough so that they can at least make it to an aid station, but it does not look good, as the color fades from Blake's face and he becomes unable to stand.