Tret's containment vessel was a class of starship utilized by Tret's species to prevent any individual infected from the Loque'eque mutagenic virus from leaving the Loque'eque homeworld and infecting neighboring star systems. This class of vessel was armed with dual forward particle cannons, and were capable of exceeding warp 4. During the 2150s, a vessel of this class was commanded by Tret.
In 2153, Tret's containment vessel, and one of her sister ships, intercepted Enterprise in orbit of the Loque'eque homewhere, where they discovered a Loque'eque aboard the Human vessel. They declared that Enterprise was under quarantine, and that it they should prepare to be boarded. The commander of Enterprise at the time, Trip Tucker refused to be boarded, but offered to Tret that he may come aboard to discuss the situation. After departing Enterprise, Tret returned to his vessel, which remained in orbit alongside her sister ship and the Earth ship.
After Enterprise attempted to flee the two containment vessels, they both took chase, and quickly caught Enterprise, after nearly disabling her aft hull plating. Threatening to destroy Enterprise, the two ships stood down after they were offered an antitoxin capable of reversing the mutagen. (ENT: "Extinction")
The containment vessel only made one appearance and was designed by John Eaves. Eaves was less than enamored with the design however, or as he has put it, "UHHHHGGGGG!!! as in ugly, by far my least favorite of anything I have ever drawn. based on a hatchet in a tool pouch it goes to show that not all shapes can inspire a spacecraft idea. HAAAA this one is embarrassing!!!". Nevertheless, the design was approved in June 2003 and was sent over to Eden FX, were the design was turned into a CGI model by Pierre Drolet whose modelling did not soften Eaves' opinion, "Even Pierre's brilliant modeling couldn't stop the fairies with ugly sticks from beating the tar out of this one!".