An energy starts to build in the opening of this climatic, dramatic chapter as Watson describes Holmes speaking with a "nervous exaltation." This unusual "gaiety" is quickly followed by Holmes telling Watson they must be "off" and asking, "Have you a pistol, Watson?"
Holmes's excitement and the question about the pistol builds tension, as the reader now expects a conflict. We anticipate violence, and yet are uncertain about what is about to happen, both of which put us on alert.
This is where Watson's role as first-person narrator comes in handy. We only experience the story through him, and at this point, he has no more idea than we do what Holmes's plan is. We have little choice but to follow after the great detective as Watson does, without information, waiting expectantly to see what will unfold.
Doyle uses short, declarative sentences from Holmes to pick up the pace of the scene and to build a sense of tension as Holmes tells Watson to take his gun:
You had best take it, then. It is well to be prepared. I see that the cab is at the door.
Tension then rises higher as Holmes and Watson catch up with their quarry, and Watson can see the "savage, distorted" face of Tonga, made especially fearful by his
features so deeply marked with all bestiality and cruelty.
This heightens the danger of the encounter, as does the poison dart Tonga is able to fire at the men before they shoot and kill him. The sense of the heroes meeting a fearsome, unpredictable, mysterious "Other" adds to our anxiety about what will occur.
Doyle effectively builds tension in chapter 10 by creating a sense of anticipation in the reader. In this chapter, we anticipate that Holmes and Watson are finally going to catch Jonathan Small, the key to the mystery of the secret treasure. The sense of anticipation lends tension to the chapter. We wonder if our heroes will be successful in their efforts to capture Small.
Doyle begins building the tension at the beginning of the chapter. After their meal, Holmes asks Watson if he has his service revolver handy. When Watson replies in the affirmative, Holmes tells him to take it with him. He tells Watson that they must be prepared for what lies ahead. At this point, we don't know what lies ahead of this excursion into dangerous waters.
When they are safely settled in their police boat, Holmes tells Watson that their craft is a fast one. It even manages to overtake a river steamer. Holmes then mentions that the Aurora (the boat they are after) has a reputation for swiftness. So, at this point, we anticipate an eventful boat ride on the waters. Essentially, Holmes and Watson may be in for a difficult time, and we don't yet know how it will end. To add to the tension, Holmes has elected not to have police backup for their mission.
Jones, the detective, voices what all of us feel at this point:
You have planned it all very neatly, whether they are the right men or not . . . but if the affair were in my hands I should have had a body of police in Jacobson's Yard, and arrested them when they came down.
Soon, Holmes spots the Aurora, and he orders Jones to give chase. Here, Doyle adds to the tension by having Holmes speak in short exclamatory sentences:
"We MUST catch her!" cried Holmes, between his teeth. "Heap it on, stokers! Make her do all she can! If we burn the boat we must have them!"
"Pile it on, men, pile it on!" cried Holmes
Of course, the chapter ends with the capture of Jonathan Small. Doyle certainly uses every tool at his disposal to build tension in the chapter. As the chapter comes to a close, we are led to wonder whether Jonathan Small will tell the entire truth about the treasure. So, the chapter ends on an eventful, tense note.
Ah, I think modern readers must find this chapter especially exciting! Are you familiar with the trope of a car chase in films, where the "good guys" must rush to catch up with the "bad guys?" Chapter Ten has very much the same content, except Mr. Holmes and Dr. Watson are chasing down their bad guys in a boat!
Doyle opens the chapter with Holmes and Watson enjoying a meal before they must do their work for the evening. They and their police fellow, Jones, set off to the wharf. Here, they get into a police boat that has been disguised by removing its identifying green lamp. Already, we can sense the seriousness of what is about to occur.
En route to their destination, Holmes explains why they are headed there. He knows that the man they are after uses a nearby dock, and Holmes has guessed that it is most likely Jacobson's Yard. Holmes also explains that the man they are looking for has acquired a boat from a local drunkard. While they are waiting in the dark just near the docks of Jacobson's Yard, the very boat they are waiting for zips behind them!
The Aurora is fast, but so is the police boat Holmes and Watson are in! On both boats, men are furiously shoveling coal into the steam-engines. As the police boat closes in on the Aurora, Dr. Watson fires at one of the men they are chasing and he falls overboard. Holmes, Watson, and their police fellows are able to rope the boats together and board the Aurora.
The sense of excitement and tension drawn from two well-matched means of transport is certainly nothing new, and it was just as powerful to Doyle's readers in 1890 as it is to us watching a car chase today!