A T'Lani warship in orbit of T'Lani III where O'Brien and Bashir help destroy the Harvester bioweapons in 2370, and where both governments then try to kill everyone involved.
T'Lani cruisers appear in the Deep Space Nine episode Armageddon Game. After centuries of war the T'Lani and the Kellerun agree to eliminate their stocks of Harvesters, a devastating biological weapon, and O'Brien and Bashir spend a week in a laboratory aboard a T'Lani cruiser working out how to neutralise the last of them.
As the final cylinder is destroyed, Kellerun soldiers burst in and shoot the scientists so that no knowledge of the weapon survives. The two Starfleet officers escape by transporter to the surface of T'Lani III, where O'Brien falls ill from a drop of Harvester on his skin.
Ambassadors E'Tyshra and Sharat give Sisko a doctored recording of an accident. When he finds his men alive, a T'Lani cruiser pursues the runabouts, and Sisko escapes by letting it destroy an empty one.