"Backstabbed in a Backwater Dungeon" is a dark fantasy anime series centered around betrayal, survival, and revenge in a treacherous dungeon world. The protagonist, a skilled adventurer, is betrayed by their closest companions during a high-stakes expedition into a remote and perilous dungeon. Left for dead in the labyrinthine depths, the protagonist must navigate the dungeon's deadly traps, monstrous creatures, and mysterious magic to survive. Along the way, they uncover hidden truths about the dungeon's origins and its connection to a larger conspiracy involving powerful factions vying for control.

The narrative explores themes of trust, resilience, and the moral ambiguity of survival. The protagonist's journey is marked by encounters with other stranded adventurers, enigmatic dungeon inhabitants, and remnants of ancient civilizations. These interactions reveal layers of the dungeon's history and the protagonist's own past, gradually piecing together the motives behind their betrayal. As the protagonist grows stronger and more resourceful, they begin to unravel the conspiracy, setting the stage for a climactic confrontation with those who wronged them.

Key characters include the protagonist, whose determination and cunning drive the story forward; the betrayers, whose motivations are gradually revealed to be tied to greed, power, or desperation; and a cast of supporting figures, such as fellow survivors, dungeon guardians, and shadowy figures orchestrating events from behind the scenes. The series balances action-packed sequences with moments of introspection, delving into the psychological toll of betrayal and the harsh realities of dungeon life. The intricate world-building and morally complex characters contribute to a narrative that is both engaging and thought-provoking.