Jamaica and rest
The imagery of Jamaica sets this novel apart from other Bond novels. The paradisal imagery of Jamaican jungles, resorts, and beaches has a calming effect on James Bond. He is able to simultaneously do his job, constantly researching, spying, learning, and strategizing, but in a restful way. The rest is the quality of his imagery setting. The glorious beauty of island life has a restful quality that makes it a suitable place to be both passive and active.
Intelligence and learning
Bond works with M to discover new threats while also securing new information about a target they are supposed to surveil. There is a conspiracy afoot, and as always, the bad guys are sensitive to intelligence agents. There are plenty of counter-intelligence efforts, like operatives of their own. They hope to find Dr. No, but that means they must be fully alert and aware of their surroundings. Their focus leads them into synchronous moments that help them to learn the right details at the right time.
Paranoia and threat
The underlying imagery of the novel's subtext is Bond's chronic awareness of death. He does not have a choice about threat detection; he can never be naïve enough to assume he is truly safe. Instead, he must move through his days (and nights) in a state of paranoia. His character's strength stems from the fact that he can function at peak levels even under the most paranoid circumstances. The concrete expressions of this imagery are the poison in the novel's opening, the poisoned fruit, the explosives and booby traps, the deadly centipede in his bedroom—etc.
Archetypal evil
What is so valuable that a man like James Bond that he is willing to risk his life again and again to continue in his mission? The answer is the imagery of Dr. No. His very name is an indication that he is not good. Bond is a good guy because he says yes. Yes, he will do what he is asked to do by his superiors. Yes, he will accept the risks of his mission. Dr. No is a control freak who uses conspiracy and power attempts to obtain more power for himself. He works for the Communists (a common motif in this genre for "baddies") and they are working on a deadly weapon that threatens the planet. Bond is not just winning points for his own government; he is saving the world from true archetypal evil.
