Fascinated
From Halopedia, the Halo wiki
Fascinated is an achievement in Halo: The Master Chief Collection. It is awarded for activating the fifth Halo 2: Anniversary Terminal on The Oracle. The achievement is worth 5 Gamerscore and can be unlocked on any difficulty.
Location
The terminal is in the room where the player is attacked by waves of Flood and Heretics. It is behind the wall opposite the door.