During the journey to the Time-Lock, Sam's car has run out of gas and the sudden appearance of Sand Whale which make Sam heading to safety. Sam now has to fight his way against Mental's horde whose try to stop him from reaching his destination. Stone has finally reached the hills leading to the Time-Lock. All he needs to do is wipe out Mental's final defense and activate the Time-Lock to start his mission.
Near the kamikaze fight — Instead of going left following the path, go straight — right, You will arrive in a dead end, look up You will see a box in the rock, destroy the box with a rocket and collect the ammo. Reward: Devastator Shells +20.
In the large area with some ruins — On the left close to the sand border next to an arch, on the side closest to the sand. Rewards: Electricity +150. Message: "Secret found".
In the large area with some ruins — Enter the central temple in this area, look up at the hole in the ceiling and shoot down the box. Rewards: Sniper Bullets +3. Message: "Secret found".
Near the Werebull fight — At the double-rock archway after the first clearing there are a bunch of boxes and ammo and a rocket crate. Beneath one of the destructible crates is some more ammo. Reward: Devastator Shells +20. Message: "Secret found!"