If this is your first go-round with Splinter Cell, pay attention to the onscreen training prompts. There’s a lot to this game and you don’t want to miss an important tip for later.
Once you’re flying solo, stay to the walls on the right, there’s more shadow. Wait for the two guys to stop talking and break apart before you move too far into the level. Be wary of light flares that take your shadows away. When you reach what looks like a corner after following the right wall, there will be a guy with his back to you. Take him out when it gets dark, and move quickly through the open gate on your right, following the wall. If you’re worried about your score, be sneaky; if you’re not, as soon as the coast is clear, you can run and a cutscene will interrupt the guys shooting at you.