Time travel is messy, and it always rewrites history. Someone has to keep track of all those changes.
And so, the Library of Time serves as a collection of books about history, all history, including the histories that no longer happened.
However, a book that tells of an alternate timeline can be a powerful weapon in the wrong person’s hands. The very existence of a book like that warps reality around it. As such, the library sends out Agents constantly in search of these books in the wild, books which they call “Rogues.”
To create an Agent, take your favorite assassin-style monster, and add the following abilities:
- When in a library, book store, or other paper-heavy environment, an Agent can misty step at will.
- An Agent holding a Rogue Book can cast one spell appropriate to that book for free, as an action. For example, an Agent holding a Rogue that’s about Benjamin Franklin might be able to cast lightning bolt. The Agent can only use this power once per book.
- Every Agent wears a chronoporter, a watch-like device that allows them to teleport up to 10 miles away to a pre-determined location. This is used to extract an Agent to a safer spot once a Rogue is recovered, or to get the Agent to a book that would otherwise be difficult to get to. However, the chronoporter has three primary limitations: It takes 4 hours to recharge, several seconds to activate, and anything (and anyone) touching the Agent when the choronporter activates comes with them.