History Literature / StarTrekDepartmentOfTemporalInvestigations

* NoSenseOfHumor: Lucsly normally plays this trope dead straight, but attempts to subvert it in Dulmur's absence with a few ''very'' dry jokes.

* YouCantFightFate: The mutability of time makes this a... complicated trope. Technically, there's not supposed to be such a thing as fate, since the future is unwritten. However, one person's future is another person's past, so this isn't strictly true. As a rule, the "good" factions are supposed to shut their eyes and ears (sometimes literally) to any knowledge of their future, because while to them the future can be changed, those who live in the future have their own version of events that they are supposed to preserve. So ultimately, it's not that you ''can't'' fight fate, but that you ''shouldn't'', or the future will be angry. Yet another reason why DTI agents have existential crises: do they really have free will when there are cops from the future who will [[{{Railroading}} railroad]] them if they wander too far from the timeline?

* InSpiteOfANail: In the alternate timeline, T'Pring still exists, and married Stonn, though with less complication since there was no Spock.

* TheNondescript: Many temporal agencies favor employees who lack defining features, as it makes them less noticeable should they find themselves in a time where their presence risks [[ForWantOfANail altering future events]]. Jena Noi, notably, is disadvantaged in this regard, being quite exotic in appearance by the standards of most humanoids from being a HeinzHybrid.

* ForWantOfANail: The Onlies timeline meant there was no Zefram Cochrane, without whom there was no Starfleet, and no Archer. As a result, the true teachings of Surak weren't found, and Romulus' influence of Vulcan was never broken, and so the Vulcan High Command - and the ''Enterprise''-era Vulcans' nasty attitudes, are still there.

* ForWantOfANail: When the artifact takes Noi, Lucsly, and Dulmur into the future, this also causes a change in the timeline in which the temporal defense grid was never invented (the details of which have been kept secret to prevent ne'er-do-wells from doing just that). This initially confuses Noi, who has no choice but to conclude that [[spoiler:Lucsly and/or Dulmur, both considered minor pawns in the grand scheme of things, must have some role to play in this galaxy-changing event.]]

* SurprisinglyRealisticOutcome: Kirk’s fun but impractical fighting style gets him in trouble, as a flying high kick doesn’t exactly work once gravity hits, you’ve spent five years doing this and a dozen more guards converge in.

The series was spun off from the ''Series/StarTrekDeepSpaceNine'' episode "[[Recap/StarTrekDeepSpaceNineS05E06TrialsAndTribbleations Trials and Tribbleations]]", the DTI's only on-screen appearance. The two characters introduced there, Lucsly and Dulmur, start as the main protagonists, but soon become only one part of an EnsembleCast.

* BuddySnapsFirst: After coming face-to-face with The Sponsor and having to listen to his SmugSnake posturing over all the chaos he's caused, Dulmur is ready to give him a bit of an attitude adjustment. To his surprise, though, his normally stolid partner beats him to it, introducing Harnoth's face to the table for [[RetGone what he did]] to Agent Shelan.

** The three ''Bozeman'' security guards who help Lt. Whitcomb break into the The Vault are named for the actors who played Biff's "gang" in ''Film/BackToTheFuture''.

* TheWatson: Vlik, the representative from Fereginar's temporal regulatory bureau, gives Lucsly an excuse to fill in some of the backstory since she and her bureau are a recent addition to the fraternity.

* IChooseToStay: [[spoiler: After convincing Daiyar to abandon her plan and redeem herself, Ranjea, who had been longing for a deeper personal connection with someone, chooses to stay in the past with her and help her heal. He leaves a future-dated message for Garcia to explain why he did it and to say goodbye.]]

* BuddySnapsFirst: After coming face-to-face with The Sponsor and having to listen to his SmugSnake posturing over all the chaos he's caused, Dulmer is ready to give him a bit of an attitude adjustment. To his surprise, though, his normally stolid partner beats him to it, introducing Harnoth's face to the table for [[RetGone what he did]] to Agent Shelan.

* HeroicWillpower: An important part of the Deltans' characterization.

* ProbabilityPileup: The novel gives this as an explanation for all the time-travel starship crews run into. Once you've done it, the chances of encountering it again increase, due to becoming a WeirdnessMagnet.