A few days after the soup incident, Billy has a disturbing experience. Late one night, due to the heat, Billy sleeps on the forecastle instead of in his hammock, stretched out alongside three other men. He is woken by a strange voice, which invites him to a secluded part of the deck. Billy, of a nature not able to refuse any request, and more than a little disoriented, follows. There, a man from the afterguard asks if Billy was impressed into service. The stranger mentions that he himself was, and that he has been talking to other men aboard the ship who were impressed. The man indirectly asks Billy if he would help in the event of a mutiny, offering Billy two guineas.
The terrified Billy, stuttering, tells the man to be gone, and the afterguardsman leaves in a hurry. In the commotion, two of the other forecastlemen are woken, but Billy's explanation puts them at ease.
Billy is terribly disturbed by the incident, and does not quite know how to wrap his mind around it. He has never been approached by any agent of secretive or underhanded business before. Later, he sees the afterguardsmen in broad daylight, and the man smiles and greets Billy as if they were friends; Billy is so thrown that he does not respond. He does not report the night incident, fearful of being a "telltale" (tattle-tale), but he does mention the incident, indirectly, to the Dansker. The Dansker is confirmed in his suspicions that Claggart is after Billy. The Dansker calls the afterguardsman a "cat's paw" but refuses to elaborate, wary of giving too much advice.
Billy, despite the Dansker's warning, does not suspect Claggart. The narrator defends Billy's innocence. His nature is simply too good to suspect the man who has always treated him kindly. Billy is no dolt, but his intelligence "had advanced while yet his simple-mindedness remained for the most part unaffected" (336). The narrator goes on to say that sailors are often an innocent, juvenile group of men. Accustomed to living within a fixed system of rules and obeying orders, they are strangers to the hazards of living in a world where every man obeys his own free will. In comparison, landsmen are duplicitous and distrustful creatures.
The small reprimands for tiny infractions stop, and Claggart's kind words grow more enthusiastic than ever. But when looking at Billy, Claggart occasionally loses control, betraying strange emotions. At times, Claggart's glance "would follow the cheerful sea Hyperion with a settled meditative and melancholy expression, his eyes strangely suffused with incipient feverish tears" (338). The emotions swing wide: at other times, seeing Billy would bring out a red light flashing forth from his eyes.
Billy thinks the master-at-arms acts strange, but does not suspect him of malice. Nor does he make anything of the strange behavior of the armorer and the captain of the hold: these men dine with Claggart, and so the master-at-arms often speaks to them in confidence.
The narrator finishes Chapter 17 saying that while Billy more or less settles back into peace, Claggart's hatred continues to eat away at him. Something is going to break.
Billy's reaction to the afterguardsman's approaches shows the boy's incredible innocence. He cannot bear to be involved in anything secretive, and his stutter kicks in. He is both angry and powerless in the face of the proposal, threatening the man with force if he doesn't leave Billy alone, but also stuttering terribly and losing his composure. Nor does Billy know how to react in the following days, when the afterguardsman tosses off casual greetings at Billy.
Melville is always asking questions about the place and responsibilities of an individual. One of many titles for Billy Budd (see Context) is Billy Budd, Sailor which emphasizes Billy's role as one unit in his majesty's navy. His duties regarding the planned mutiny are to report the suspicious activity, but he has a schoolboy's sense of honor and will not betray his fellow sailors. That is one choice Billy makes, and indirectly it costs him his life; had he come forward right away, Claggart's later accusation would not have been possible. Many of the other characters also deal with duty: Vere will act out of duty later on. The Dansker, on the other hand, absolutely refuses to get involved in anything, even in a situation that seems to threaten his young friend's safety. He has apparently reached the conclusion that non-interference is the best way to preserve himself.
Melville connects Billy's innocence to his vocation, and also makes a connection between innocence and a life of constrained will. Two themes come together here: innocence and principle, the two forces embodied in Billy and Captain Vere. Life lived within systems, obeying orders, makes an ease of trust possible that is unknown to landsmen. Certainly, Melville is commenting on the power of law and principle in controlling and improving men. Yet the affects of such a system are not unambiguous. Billy's lack of experience in the world of free wills also makes him somewhat helpless. And, of course, despite what the narrator has said, we have evidence that not all sailors are innocent. Billy has become entangled in a conspiracy of some sort. However, Melville does make his conspirators transplanted landsmen. He hints that the afterguardsman may not always have been a seaman, for he is "chubby too for a sailor, even an afterguardsman" (334). Claggart, if he is involved, is new to a naval career as well. Still, although Melville makes the conspirators somewhat more removed from the world of the sea, the fact remains that ships, also, can be dens of evil, and that law can be manipulated.
Again, we see mysterious, unsettling hints of Claggart's conflicting feelings for Billy. When Billy passes, Claggart sometimes has involuntary tears in his eyes: "Yes and sometimes the melancholy expression would have in it a touch of soft yearning, as if Claggart could even have loved Billy but for fate and ban" (338). This language suggests desire, and passion: Melville uses the ambiguous word "passion" again and again to describe Claggart's feelings for Billy. But the emotions swing wide. Melville gives us an impossible, unreal image to describe Claggart's rage: "But upon any abrupt unforeseen encounter a red light would flash forth from his eye like a spark from an anvil in a dusk smithy" (338). The image has to be metaphor, but even so it is unsettling and supernatural. Claggart, though given a real psychology that develops and partially explains the nature of evil (he is arguably given more motivation and psychological depth than, say, Shakespeare's Iago), is also an allegorical stand-in for the devil.