The Aurbical Abacus was an ancient Yokudan relic created by distilling the knowledge and wisdom of twenty generations of the priest-wizards of the Yokudan god Zeht. It had the physical appearance of having glass gears and ivory pistons, and suffused with the blue glow of star-magic. It was used to track the movements of the moons, constellations, and planets and calculate the exact turn of the seasons. It detected the directional origin of star-magicka, or "varliance," and stored it as data. It can also predict the weather and even control it on a continental scale. It was brought to Hew's Bane after Yokuda sank, by the Zeht priesthood, where it was buried in the old Hubalajad family tomb known as Bahraha's Gloom.
Circa 2E 582, the Morag Tong assassin Naryu Virian uncovered a plot within the Morag Tong to coordinate a coup to take over the Tong. It involved obtaining various goals, some involving objects, and one of them was to obtain the Abacus. The people who were involved in this plan were called the Seven Secretives, and she tracked one of them down to Bahraha's Gloom. Naryu put on an ancient Zeht Priestess regalia as a disguise and came across a coffin. When she touched it, she awakened the tomb's guardian, a Mournful Aegis. The Secretives planned to set a trap, allowing her to get killed by the Aegis, but it backfired, as the regalia allowed Naryu to go unharmed, and the Aegis killed the plotter. Within the coffin she found the Aurbical Abacus and smashed it to pieces.[1]