One afternoon in Antigua, Rooke learns what the oath to serve and obey truly means. Some officers had begun to plan a mutiny. They hadn't done anything but talk about it, but their leader was sentenced to hang. Rooke watches as the man jerks on his rope, feeling as though he has to keep watching. When the man is finally dead and others cut him down, Rooke tries to take a deep breath but moans instead. The lieutenant's companions then stand in front of the assembly while their commander uses his sword to cut off their badges and their brass buttons. Then, they're shown out the gate. Rooke realizes that while those men are technically alive, they might as well be dead because they'll never be able to find a place in the world.
This experience shows Rooke that both words and secrets have enormous amounts of power—combined, they can result in symbolic or even physical death. By insisting that Rooke and his fellow soldiers witness this brutality, the military turns it into a communal event. This implicates Rooke and every other watching soldier in the violence, hence Rooke's extreme emotional reaction to seeing it. Rooke's realization that the two living soldiers are as good as dead suggests that Rooke currently sees the military as the only place he can find community.
Rooke thinks that every officer had watched the hanging because they had to, and nobody who watched would ever forget what they saw. He realizes that underneath the charm of the armed forces, there's horror and violence. Further, he realizes that he'll pay for his involvement in the "mighty imperial machine," and must suspend his emotion in order to continue to be involved.
Rooke knows now that the military doesn't just carry out violence against others; those who are a part of the military are at just as much risk of becoming a victim of violence themselves. By feeling implicated in this violence, he recognizes that he does have power to either accept or reject this kind of violence.
Late in 1781, Rooke prepares for his first battle against a French ship. He and Silk take their places, and Rooke reasons that combat is just a matter of distance and the trajectory of one's bullets. When the fighting starts, Rooke remembers practicing reloading his gun, but thinks that battle is entirely different from such practice. The deck becomes a confused mess of smoke and screams. A rope hits Rooke in the head and as he tries to get to his feet he's knocked sideways again by a blast. When he gets to his feet, he sees Private Truby lying on the deck, trying to get up. Truby's entire lower half is nothing more than a bloody, steaming mass. Rooke and Silk stare as Truby tries to figure out why he can't stand. Rooke doesn't remember being knocked unconscious minutes later.
This kind of violence is entirely irrational. For Rooke, Silk, and Private Truby, it's primarily emotional and, more than anything, terrifying. This makes it abundantly clear that there are limits to how much Rooke can rationalize violence successfully, no matter how logical he tries to be. Though Rooke is semi-successfully able to keep reloading his musket, the entire rest of the battle isn't something he can control. Through learning this truth, Rooke discovers that he can no longer believe anything positive about the military.
When Rooke wakes in the hospital in Portsmouth, the doctors tell him he's lucky to be alive. Anne sits with Rooke for hours on end, and he feels as though her hand holding his is all that keeps him from slipping away. When he's well enough to get out of bed, he begins walking the streets of Portsmouth and finds himself often on the pebble beach he visited as a boy. The first time he goes he tried to find his pebble collection, but it's long gone. When he cries, he reasons that the injury makes it so he feels like he has lost everything.
Rooke is right; the horrors he saw on Resolution render him unable to think rationally or scientifically about things while he recovers. This again suggests that violence and rationality aren't necessarily compatible. While the British army can mechanize violence, experiencing it most certainly has a negative human toll that cannot be reasoned away.
Rooke sits on the cold pebbles and watches the water, thinking that his life is suspended in time and he has no hope of a future now that he has seen the evil of battle. Two years after the battle on the Resolution, the war ends, the English having lost. When Rooke meets Silk not long after, he realizes that the war changed Silk, who seems defeated and bitter. Rooke realizes that their friendship was deepened after watching Private Truby struggle on the deck.
The fact that Rooke feels as though his life is entirely derailed by violence makes it very clear that though he uses unemotional, scientific thought processes to cope with life, he is also an inherently emotional person. This in turn suggests that one of Rooke's projects throughout the rest of the novel will be to learn how to accept the emotional person he truly is.
As Rooke's health improves, he begins to tutor students in math, astronomy, and languages. Their slowness irritates him, and Anne teases him often that his injury didn't do any good if it didn't make him stupid like everyone else. He teases her back, but wonders how he'll ever find a life for himself.
Once again, Rooke's intelligence alienates him from those he might build a community with. This shows that Rooke will also need to learn how to reconcile his intelligence with the thought processes of the rest of the world, if he wishes to truly become a part of it.