^Again, folks, don't confuse the DTI with the time agencies of future centuries. As portrayed in my novels, the DTI does not travel through time
, except in the most extreme emergencies. The 24th-century Federation does not yet have reliable time-travel technology of its own, and the alien artifacts the DTI has in its custody are too poorly understood and too powerful to be used casually. Remember, the "I" stands for Investigations, not Interventions. The DTI investigates incidents of time travel after they occur, catalogs and documents them, assesses the legality of the actions of involved parties, tries to determine if any timeline alteration has occurred, tries to contain or isolate whatever natural phenomenon or alien technology may have caused it, etc. Think of them like, say, the Centers for Disease Control -- an agency that investigates "outbreaks" of a harmful phenomenon, that tries to contain them, to identify their origins, and to prevent their recurrence, even though that phenomenon is largely beyond their control and often the best they can do is limit the damage. Expecting the DTI to practice time travel itself is like expecting the CDC to release plagues or the DEA to smuggle drugs.