In the book "Sentinel" by Jennifer L. Armentrout, the theme of karma is explored through complex characters facing the consequences of their actions. The notion that karma can deliver harsh retributions is a central idea, indicating that one's deeds can return to haunt them in unexpected ways. This sense of inevitability adds a weight to the narrative, as the characters grapple with their past choices and their impacts on the present.

The quote "Karma was a bitch and a half" succinctly captures the essence of this theme, reflecting a sense of frustration and acknowledgment of the relentless nature of fate. It suggests that the characters are not only aware of their missteps but also the inevitability of facing the repercussions. Armentrout's storytelling weaves together these themes, creating a compelling exploration of morality, consequences, and redemption.