The Porthoy was a Kuat Systems Transport II freighter that was used by the Metatheran Cartel during the waning years of the Galactic Republic. Circa 31 BBY, the Cartel used the starship to mine some gas deposits from the Cularin system asteroid belt, then maneuvered the ship so as to leave the Cularin system. However, just as the Porthoy was passing the planet Almas, the Almas Sith fortress produced a gigantic bolt of Force lightning, in an attempt to destroy the Darkstaff, a powerful Sith artifact. The lightning bolt struck the Porthoy, damaging the ship and altering the gas aboard it, while the temporal effects of the Darkstaff caused the Porthoy and the entire Cularin system to be transported ten years into the future, to about 21 BBY.
Noticing that the gas had changed, the crew of the Porthoy flew the freighter to the nearest neutral port, Oluna Biqua on the planet Genarius, to study the gas in a laboratory. However, while the Porthoy was being unloaded on Oluna Biqua, it was involved in an accident with a motorized loader. The loader opened the side of the Porthoy, which ignited a fuel line and caused an explosion that destroyed everything on board the ship, including a canister of the altered gas. The gas released by the explosion subsequently infiltrated Oluna Biqua's air circulation system and granted the city's population pseudo-Force powers, driving them insane.