Back in the Field is an achievement/trophy you can get during the “Deep Cover” mission of Modern Warfare 3. To earn Back in the Field, you’ll need to grab the Major’s keycard — a key objective of “Deep Cover” — within 90 seconds without being detected.

“Deep Cover” is tough enough mission in its own right; Back in the Field adds an extra layer of challenge. Here’s how to get the Major’s keycard in 90 seconds flat, and how to get the Back in the Field achievement/trophy in Modern Warfare 3.

How to get the Back in the Field achievement in MW3

During “Deep Cover,” you play as a disguised soldier who needs to access a room and talk to your contact. Staying stealthy is crucial for completing the mission.

Keep in mind that you can still earn Back in the Field even if you’re discovered and killed by enemy soldiers after grabbing the key card, so you just have to stay concealed during the first part of “Deep Cover.”

Here’s the fastest path for you to grab the Major’s keycard in “Deep Cover” without getting detected:

1. Once the mission begins, sprint and jump over the wall of sandbags to save time. You can sprint up until you’re close to a parked truck on the left side of the road. Be careful with a truck that is driving alongside you. If you get too close or run beside it, the enemies will spot you.

Image: Sledgehammer Games/Activision via Polygon

2. While walking, avoid the two groups of soldiers heading toward you — one on the left and the other on the right.

Image: Sledgehammer Games/Activision via Polygon

3. Next, instead of following the same path as the truck, go inside the building on the left and walk close to the walls, trying to keep your distance from the soldiers.

Image: Sledgehammer Games/Activision via Polygon

4. In the next section, you can see the truck parking close to a security cabin. First, you need to go behind a soldier who begins walking toward you; then, you can pass the cabin. While the soldier inside might look at you suspiciously, they’ll quickly forget you.

Image: Sledgehammer Games/Activision via Polygon

5. Once you are in the new section, go straight ahead until you see an officer leaving the building followed by two guards. You can turn around and hide inside the building beside the cabin or between two trucks parked close to you to wait for the right moment.

Image: Sledgehammer Games/Activision via Polygon

6. The best approach to get the key card in time is to wait until the last guard with the officer is far from two stationed soldiers to go behind them and start climbing the stairs following the Major. Don’t wait until the soldiers stop walking to get close to the stairs. You must keep a safe distance from them, but once the Major is almost inside the room at the top of the stairs, you need to get close and use the Takedown command.

Image: Sledgehammer Games/Activision via Polygon

Once the animation is over, you can find the keycard on the ground.

For more Modern Warfare 3 guides, see how to earn the A Shot Blocked trophy, learn where to find all items and weapons in “Precious Cargo,” or check out our walkthrough for “Deep Cover.” If you’re jumping into multiplayer when it goes live, check our guides on the best Striker loadout, best MCW loadout, and best AMR9 loadout.