You're in Mother Goddess Temple now. As you enter, you'll see a woman with a some guys looting the sanctuary. Enter the next room and kill the troll there. There are three paths from the room (four with the one you've entered it). You can't take the one in the middle yet (you need the four keys) so let's go right (#1) and watch the scene. Don't go further where the elves are - stay by the entrance for a while and observe as they wander from one side of the room to another. Wait a moment till both groups go to the chambers on both sides - then send three of your minions to each of the wheels left and right to lock the elves and leave them there for a while. Be patient and make sure no elf stays outside the chambers cause you'll have to repeat it all over again. Once they're locked send another 3 minions to the tomb in the middle of the room (#2). You've got one of the keys.
Come back to the room with three exits and take the one to the left now (#1). You'll find 4 tombs in the room and the key is in the first one to the left as you enter. Watch out for the elves - they keep moving in and out to the neighboring room - they'll be watching you. But they're so slow you can avoid direct contact with them and do your job there. So, two more keys to find. Go back to where you've locked the elves, walk past the tomb and enter the next room (#2). You've got the same problem here as in the previous room - just there are more elves, more chambers, more mechanisms and they are more difficult to access. There are more tombs to check out, too, but only one of them holds the key. Well... you've got little else to do except for waiting and observing the elves. And remember to guide your minions directly to the mechanisms in the right moment.
Come back to the room to your left - where you've got the first key. You'll see passage to the next hall there (#1). You'll see tombs on both sides but no key there! - you can check it out for yourself - just prepare for a battle with some men in black (there' brown spawning pit by the temple's entrance and another one a few steps further in the room you're in). Once they're down look around and you'll see an alcove (#2) and few more tombs behind it. There are some elves guarding the one to the right - and that's where the last key is. Attract the elves' attention and send some minions to get the key. Now you've got all 4 of them!