"A curious historian and a skilled engineer from an ancient civilization team up to unlock the secrets of time travel, only to discover that their meddling with history may have caused the catastrophic event they were trying to prevent."
Protagonist: A curious historian who stumbles upon the ancient civilization's time-travel technology; Deuteragonist: A skilled engineer from the ancient civilization who helps the protagonist understand and utilize the time-travel technology.
The protagonist discovers the ancient civilization's time-travel technology and becomes determined to uncover its secrets, leading to a dangerous journey through time and space.
The protagonist and deuteragonist work together to unlock the mysteries of time travel, facing numerous challenges and dangers. In the end, they successfully harness the power of time travel, using it to reshape history and prevent a catastrophic event from occurring in their own time. The novel concludes with the protagonist and deuteragonist returning to their own time, forever changed by their extraordinary journey.
Twist: The protagonist discovers that the catastrophic event they were trying to prevent was actually caused by their own meddling with time, leading to a moral dilemma and a race against time to set things right before it's too late.