Zeus Quest - The Rebirth of Earth

In the area after the labyrinth, take a stone from the pile near the well, and drop it down. Then pick up another. Use the Time Machine on the well, and drop another stone down, and you will get a lever. Use your ambrosia on the large tree, then show the researcher your lever, and he will give you a stone tablet.

Exit this area and back to where the labyrinth entrance was, and use the tablet on the gap between the horns in the structure in the middle. Take it back, and then return to the previous area (you don't have to navigate the labyrinth again, don't worry).

Here, give the tablet back to the researcher, who will refuse it. Use your lightning spear on him, and he will succumb and give you the proper tablet.

Go back to the labyrinth entrance area, and put the good tablet in the gap. This time it will work. Click on the pillar with the hieroglyphs on, and then select "Human Head" then "Torch". No we can collect the Disc of Phaistos.

Return to the other area, and use the lever on the hole in front of the electricity, then interact with it. Talk to Europe, then use your lightning spear on the researcher so he goes away. Talk to Europe one more time to say goodbye and unlock this.