At the conclusion of Star Trek: Nemesis, Commander Riker finally accepted a promotion to captain and was given command of the USS Titan. Despite the movie being released in 2002, it marked the end of The Next Generation era, and so it’s taken until now for the ship to be depicted on screen, as we finally saw it in the first season finale of Star Trek: Lower Decks.
The episode revolved around the USS Cerritos encountering the Pakleds, a species generally considered a joke due to their rotund appearance, simplistic speech and considerably less advanced native ships. However, their constant mission to steal the technology of others with which to augment their own spacecrafts led to them acquiring enough upgrades to become a formidable force, first destroying the USS Solvang and crippling the Cerritos.
After the Cerritos managed to destroy one such chimeric dreadnaught through a daring infiltration, a further three appeared and immobilized the vessel, and were about to tear it apart before the Titan came blasting out of warp in a Big Damn Heroes moment soundtracked by The Next Generation theme music, with the subsequent effortless show of force forcing the Pakled ships to retreat.
As well as taking the Pakleds by surprise, who were otherwise occupied and unable to engage the new threat, the Titan is a considerably more powerful vessel. The Cerritos is a California-class starship, a designation created for Lower Decks but suggested to have always existed, and primarily intended for utility and support missions. The Titan, meanwhile, is a Luna-class, created following the end of the Dominion War when Starfleet turned back to deep space exploration. While not as vast as Sovereign-class ships like the Enterprise, it was intended for similar missions, and so is considerably more heavily armed and armored than the vessel it saved.
The visual appearance of the Titan hews very close to its depiction on the covers of a series of novels detailing the adventures of Riker and his crew, but it turning up in Star Trek: Lower Decks now makes the design canon, and may well form the basis of other ships of its class in the future.