When you enter the cave beyond the pillar and mud pool, the chime rings for SECRET #3.

Splash through the shallow mud until you come to a pool of clear water. Swim down on the right side to get some flares from the bottom. Then swim to the far side of the pool and walk out of the water. Keep to the right here...

...so Lara doesn't get singed when Nessie pops out of the crevice on the left breathing fire.

Wait for Nessie to raise her head to take a breath, then jump into the small square pool under her neck.

Swim down, following the underwater passage through several twists and turns. When the passage widens and you see Nessie's belly above, swim down along the right side of the cave to find a small tunnel in the rocks. Go through here...

...to a pool where you can surface. You can't climb out of the water onto Nessie's back; it's too steep. But there is an opening behind her front flipper.

Swim through to emerge in a control room. Climb out at the right end near the large medi pack.

Kill the guard in the control room on the other side of the pool.

Cross over there. Note the schematic diagrams of the mechanical monster and the map of the lake on the walls. Perhaps pause to wonder how much Lara will be paid for her article debunking the myth of the Loch Ness monster. Then pick up the grenades and go inside.

Use the switch on the right side of the cockpit to open the gate on the other side.

Exit this way, killing a red-eyed dog about halfway up the stairs.

Continue to the top of the stairs. When you reach an apparent dead-end, climb the ledges...

...

...and slide down to the STEPPED PATH. Turn right and follow the path down to the bottom.

[Part 1 | Return to the Highland Fling Walkthrough]