Final answer:
The subject deals with characters in literature who behave suspiciously, causing others to become wary or curious. This typically leads to crucial plot developments and can result in uncovering secrets or betrayals.
Step-by-step explanation:
The question revolves around a recurring theme of characters behaving suspiciously or oddly, leading to hypotheses, discoveries, or raised tensions among other characters in various works of literature. Instances where Finn notices Jez or other characters like Jennie, John, and Dexter observe their peers for peculiar behavior, illustrate a common narrative device used to develop plot or build suspense. These observations often lead to pivotal moments in a story, such as the uncovering of secrets, realization of betrayals, or shifts in relationships. For example, when a character like Jez is seen engaging with something suspicious, it could hint at an impending revelation or conflict that would drive the narrative forward.