1. Drop to the water below and steer your boat to the right.
2. The lambda is the signal to exit your boat and climb the ladder.
3. Walk behind the building and enter that doorway ahead.
4. You've arrived at Eli's. Stay put until the decontamination process completes.
5. Follow the good Doctor as she escorts you to the lab below.
6. I look forward to these scripted sequences. Take a look around the lab and enjoy your arrival.
7. Before long, Alyx shows up and has a minor cat fight with the competition. Follow Alyx to the next area.
8. Alyx hands over an original and well-implemented weapon concept - the Zero-Point Energy Gun (gravity gun for short).
9. A stacking puzzle and this brilliant game of fetch with a mechanical "dog" allow you to become acquainted with the gun's use. Before long, though, a chopper attacks and you're forced to backtrack.
10. Follow Dog and he'll open the tunnel to Ravenholm. Proceed through.
11. Use your gravity gun to remove any obstacles in your path.
12. Shoot the lock on this ladder then climb it to the area above, where the next level will load.