To find the lockbox, the team must interrogate 5 enemy players. The interrogation is like an execution, but takes longer to kill. Once 5 enemy players are interrogated, the lockbox will be revealed at a random location, usually near where the defending team currently is.
The team will then have to unlock the lockbox by standing next to it and press triangle. A lock with a circle around it saying Attack will show the process of unlocking it. It fills in three stages and informs both teams on the currant status of each box when a third is filled each time.
If the circle fills completely, the lockbox is open and the team wins the game. If the opposing team interrogates 5 players, then the team's lockbox is revealed and a meter saying Defend will be on the lockbox and will show the unlocking process. If the enemy team manages to unlock the safe, then the team defending it will lose.