The Palpatine's Storehouse was an uncharted asteroid in the Deep Core which had been one of Emperor Palpatine's secret research facilities during the Imperial era. It took six separate jumps into hyperspace and twice as many hours to get to the asteroid since there was no direct route available.
This asteroid depot was a maze of pressurized domes, tunnels and sealed chambers storing various biological weapons capable of affecting a wide range of species including the infamous Krytos virus and a Human-specific virus known as the Emperor's Plague. Its central hub stored the majority of these viruses and was filled with rows of cylinders and tanks. There was also a series of docking bays on the rim of the plague storehouse. Several sealed chambers contained the deceased corpses of experimental subjects who were predominantly non-Human or other enemies of the Empire.
- "Tell me where the rest is stored. This is your final chance. Very well, then face the consequences."
- ―Nolaa Tarkona interrogating the last of the four Imperial Royal Guards who led the Second Imperium's insurgency in 23 ABY[src]
This plague storehouse had once been the headquarters of the Imperial scientist Evir Derricote who had been responsible for the Krytos virus—a bioengineered virus which afflicted countless alien species following the Liberation of Coruscant in 6 ABY. Prior to his first death at the Battle of Endor in 4 ABY, Palpatine ordered that samples of the human-specific Emperor's Plague be stored in the hidden weapons depot. He also had the depot's coordinates removed from Imperial archives to hide its location. Only a few high-ranking Imperials were aware of the existence of this station and its depot.
In 24 ABY, an alien scavenger named Fonterrat came across the Emperor's Plague Storehouse. Though the Galactic Empire had been defeated, this plague warehouse still remained with its supplies of deadly diseases. He then offered to sell a navicomputer module containing information of the plague storehouse to Nolaa Tarkona knowing of their hatred of Humans though he refused to deal directly with her, suggesting that she sent a neutral party to meet him on Kuar.
When negotiating, he also provided her with one sample of the virus which she use to seal his payment. The neutral party turned out to be the a wealthy Human merchant and shipping tycoon named Bornan Thul, the owner of Bornaryn Trading. In exchange for the navicomputer module that contained the coordinates for the asteroid, Bornan paid with a time-locked case filled with credits. Bornan was then supposed to deliver it to Nolaa at a trade conference on Shumavar but he found out about what lay within the plague warehouse and went into hiding.
Nolaa also captured the last surviving member of the Imperial Royal Guards who had led the Second Imperium's insurgency in 23 ABY and interrogated him over the location of the weapons depot so that she could lay her hands on its deadly cache of biological weapons. When he refused to cooperate, she had him murdered by using a sample of the Emperor's Plague.
Enraged, Nolaa hired numerous bounty hunters to locate Thul and bring back the navicomputer. Among those bounty hunters was Ailyn Vel, disguised as her father Boba Fett. In response to this, his son Raynar Thul—who was a Jedi trainee at the Jedi Praxeum on Yavin 4—along with his Jedi companions Jacen, Jaina Solo, Tenel Ka, the Wookiee Lowbacca and his translator droid M-TD went on his trail. They would later be joined by Zekk. After encounters with bounty hunters and visits to several worlds including Mechis III and Ziost, they caught up with Bornan and learned the reason he had gone into hiding.
They then manage to find the asteroid depot and plant explosives in it. However, a Diversity Alliance fleet under Nolaa herself arrived. During the ensuing chaos, Bornan and several of the Alliance members including Nolaa herself were infected with several deadly plagues released from smashed canisters and tanks. Bornan contracted a Human-specific virus and died.
Help for the Jedi arrived in the form of the New Republic Defense Fleet and the Bornaryn Trading Fleet which defeated the Alliance fleet during the ensuing battle. After the Jedi evacuated the asteroid depot, the combined New Republic/Bornaryn fleet destroyed the plague warehouse, thus destroying the plagues stored within it. Nolaa Tarkona managed to escape with the Wookiee Raaba on her transport Rising Star though she later died on an uncharted asteroid in the Outer Rim.
It is unknown how the warehouse came to contain Krytos virus samples, when it was closed off before the virus was actually invented.