From publisher blurb:
So you messed up and killed your entire party.
Wouldn't you like to go back in time to fix things? Thanks to chronomancy, now you can!
This campaign setting features two new species; 5 new subclasses; 20 new monsters; and over 70 new chronomancy spells. Also included are rules for including time travel in your campaign, paradox, and the effects of lifelines and the Temporal Plane.
But be careful! Time travel isn't for the faint of heart, and the consequences of messing with time can invoke a paradox that can have unforeseen consequences. Worse, several time-traveling species jealously guard the timestream and execute trespassers with extreme prejudice.
Still, a chance to fix things may be too good to pass up. So what are you waiting for? Grab your timepiece and that laser pistol you found; your future self will thank you yesterday!