The first Assassin's Creed game introduced the Animus, the machine that accesses genetic memories. In the modern-day storyline, Abstergo Industries uses the device to make Desmond Miles relive the memories of his ancestor Altaïr Ibn-La'Ahad.
The Animus provides the narrative bridge between the modern world and historical settings. Rather than functioning as ordinary time travel, it presents a person's inherited memories as reconstructed experiences accessed through DNA.
Later games expand the technology and introduce other users, versions, and portable systems. Because the Animus appears prominently in Assassin's Creed II and many sequels, some players associate its introduction with Ezio's story. However, the concept and the machine first appeared in the 2007 original, where Desmond's sessions form the modern framing narrative.