Undercover

Walkthrough
When everyone boards the truck, drive down the road and turn left. The first soldiers will let you pass.

When you reach the next roadblock, you will encounter a checkpoint. Your group is forced to attack, and has to abandon the truck there. The group moves towards the forest to the right, while under fire from enemies back on the main road.

There are a few Russian guards within the forest. These will most likely injure most of your team, but skilled players can snipe them before they are too much trouble.

Continue south to the castle; once the team leader announces you're five minutes away, there should be no other opposition.