The mood of Cloud Atlas is contemplative on the larger scale of the novel, which meanders through several periods in time and history. There exists a level of emotional disconnect from the stories themselves, with readers learning characters' fates before the narrative returns to their tale. The interconnectedness of the stories, however, makes the reader feel connected to all of humanity in an abstract way, the world made both small and large by the perspectives of an entire species and told throughout its history.
Cloud Atlas engages both directly and obliquely with pressing social issues at multiple points in history. Certain narrators, like Adam Ewing and Robert Frobisher, employ casual sexism and racism in their narration. Sonmi directly addresses pressing human rights and labor violations. These serious topics prompt conscious readers towards a mood of serious consideration.
Such serious consideration may conflict with the narrator’s tone at any given moment, especially if it is the narrator’s perspective the reader should criticize. Robert Frobisher, for example, often employs a flippant tone when speaking of his various criminal enterprises, or when denigrating the women and girls around him. Frobisher even employs humor; yet, in such moments, the thoughtful modern reader is likely to be unamused. This disconnect between mood and tone becomes more pronounced as a given narrator becomes more unreliable.