Storage Facility Z98 was a base built and operated by the Solanae, a servitor species to the Iconians. Its purpose was to supply and transport servitor troops for Iconian expansion and "pacification" actions. In 2409, its existence was discovered by the Allies. Z98 was staffed with Solanae and automated, floating guardians. (STO mission: "Sphere of Influence")
Storage Facility Z98 possessed 220 docking ports and troop capacity of 4.7 million "units". Live observation of several worlds was possible from Z98. In 2409, at least six planets were under constant surveillance: Earth, Qo'noS, Vandros VI, New Romulus, Iconia, and Quarra.
Facilities at Z98 included a weapons control center, a brig and medical bays for examination. These were reminiscent of a subspace location Starfleet had encountered in 2369. (STO mission: "Sphere of Influence", TNG episode: "Schisms")
Storage Facility Z98 had access to the Iconian gateway network, which covered the Milky Way and Andromeda galaxies. This network included gateways large enough to transport starships and which were hidden in subspace as well unless activated.
In 2409, a group of stranded Alliance officers discovered the station and scouted it, discovering its purpose. The Solanae captured all of the Allies except for Ambassador Worf and another officer. They conducted experiments on Captain Va'Kel Shon and Commander Maiek, which resulted in Maiek's death. Worf and the others reactivated the dormant Iconian gateway network while deactivating the gateway on New Romulus to prevent further seismic stress to the planet. They accessed one gateway to escape to Obelisk 1, a Solanae carrier. (STO mission: "Sphere of Influence")