The Ash Key is puzzle #14 in Virtual Villagers 3: The Secret City.
- Level 2 Leadership
Complete a weather dance, then wait for the fire to burn out. Once it does, you will see a diamond appear in the ashes. (If, for some reason, your fire goes out before you complete the weather dance, you will have to start the fire over again.)
Send some villagers to the waterfalls that are on the left side of the scene, and they will automatically pick up some water and throw it on the diamond.
You will have to keep dragging your villagers over to the water several times until the key is cool enough to pick up.
You will know that the diamond is ready to be picked up once you drop a villager over to the waterfall and they drink out of it instead of carrying water back to the pit.
Once that happens, drop any villager onto the pit, and they will take the diamond to the door.