Apis is a sacred bull considered by ancient Egyptians as an aspect of the creator god Ptah, worshipped in the city of Memphis. As one of the most important animals in Egypt, the bull was characterized by the white markings on its black coat to demonstrate the presence of the god within the bull.
The bull lived as royalty in the Temple of Ptah, where it served as an oracle and an object of worship for a maximum of twenty-two years. Upon its death, the bull would be mummified and interred in a cemetery in the Saqqara Nome outside the city.
Once buried, the priests would begin a search for bull's successor, which had to have appropriate markings to replace the deceased one. Once chosen, the bull would be installed in the Temple of Ptah, accompanied by a lavishing ceremony lasting seven days.
In 48 BCE, Hetepi, a member of the Order of the Ancients and a priest of Anubis, sought to sabotage the reputation of the High Priest Pasherenptah so that he could take the position. To this end, he captured Panchrates and forced his sisters, the twin priestesses Taous and Tawe to poison the bull by feeding it peach pits. Sure enough, the bull fell sick, causing Pasherenptah much distress in the upcoming procession ceremony.
In response, Pasherenptah sent the Medjay Bayek of Siwa to investigate the source. Later accompanied by his wife Aya, they uncovered the source of the bull's sickness, causing the twin priestesses to reveal the truth for their actions. After Bayek rescued Panchrates and assassinated Hetepi, the bull recovered and the procession ceremony commenced, with the pharaoh Cleopatra in attendance.