Join the Domain.
Halo 4 has seven Terminals, scattered throughout the campaign, that you’ll need to find to get the “Contact the Domain” and “Terminus” achievements. This guide will explain where every terminal can be found, and will show you in the video below that. We must warn you though, the video and terminal location descriptions may contain mild SPOILERS.
Terminal 1 – Mission: Requiem – right before you go up the elevator inside the Forerunner building, go around behind the organge ramp to find this terminal.
Terminal 2 – Mission: Forerunner – When Cortana is talking to you about rampancy, look under the door you’re supposed to go into for a terminal.
Terminal 3 – Mission: Infinity – after you meet up with the other marines wait for the cut scene to end and then turn 180 degrees to find this Terminal.
Terminal 4 – Mission: Reclaimer – after you retrieve Cortana, fight your way through the first room and look right as you go through the door to find this terminal.
Terminal 5 – Mission: Shutdown – after flying to the third tower, go inside and follow the light bridges to the back of the room on the leftmost platform if you’re looking straight ahead from the entrance.
Terminal 6 – Mission: Composer – after locating the doctor, go out onto the open area of the asteroid, head right, and look for a small circular cave opening. The terminal will be in the cave.
Terminal 7 – Mission: Midnight – in the center of the third room, shortly after the mission begins.