Tree Gnome Village

Getting started
Talk to King Bolren in the centre of the Tree Gnome Maze. He will say that three orbs have been stolen by Khazard troops. Agree to help him, and you will be taken out of the maze.

The three trackers
Items needed for this part of the quest: 6 normal logs.

Head north to the southern edge of the Battlefield and speak with Commander Montai, who is wearing red clothing. He will ask for you to get 6 logs to repair their defences. Supply him with the logs (if you don't have it you can still kill the maze goblins to get an axe. However, this will likely take a very long time and it will usually be faster to simply go back to a bank), and he'll tell you that three trackers that have been sent out to retrieve coordinates to fire the ballista have not returned. He asks you to find them.
 * The first tracker is behind or on the side of the biggest building in the north-west.
 * The second tracker is in the north-east building behind the cell.
 * The third tracker is roaming outside the south-west corner of the stronghold.

The first two trackers will give you the coordinates you need, which you'll automatically commit to memory. The third tracker, however, has been driven mad as a result of the chaos. Though most of what he says is garbage, he will give you a hint as to the number you need. You may have to do a bit of guesswork, though. For instance, "Less than my hands" would equal 1, where "More than my head less than my fingers" could be 2, "More than we but less than our feet" is 3, and lastly, "My legs and your legs" is 4. (It should not be any other possible number so try and remember what the third tracker said.)

Head back to the ballista (not the catapult, which is next to Montai), which is located in the south-west corner of the battlefield, and you'll be given a chance to enter the third coordinate. It will be a number between 1 and 4. If you miss, just try again until you get it.

The orbs
Once you get a hit, talk to Commander Montai once again then walk north to the stronghold (building where Gnome Tracker 1 was) and climb over the crumbled wall. When you do, you will be attacked by a level 48 Khazard commander; they have low Hitpoints (22) and should not be troublesome for most mid-leveled players (can be safe-spotted behind northern broken chair). You can skip defeating the commander if you wish and proceed through the door into the other room.

 WARNING to Hardcore Ironmen:  When you climb over the wall, a brief conversation will appear with a Khazard commander asking you how you got in. At the same time, he may attack you several times. The hits will not show up immediately but rather when the conversation is done, so be extra cautious if you have 12 Hitpoints or fewer. 

Once in the other room, go up the ladder, retrieve the missing orb of protection from the chest inside. The commander in the room will attack you once you open the chest but just run back down the ladder and out of the nearby door.

Return to the Tree Gnome Village, and talk to Elkoy to be sent to the centre. King Bolren will then tell you that the other two orbs of protection have been stolen by the Khazard warlord.
 * Note: If you fight the warlord before talking to the King again, you will have to fight him again as the orbs won't drop the first time.

Exit the village and start heading north-west, past the level 64 wolves to the southwest edge of West Ardougne, just below the Underground Pass. Talk to the Khazard warlord and kill him to retrieve the other two orbs. Although he has a rather large health pool of 170 HP, he does not hit often. Players with Rune armour and weapons should have little trouble fighting him if they have a small amount of decent quality food. Magic or ranged can also be used easily by continuing to move outside the range he can walk to. Magic users can safespot the Khazard warlord by moving just out of range behind the small hill. The warlord will stay on the other side, and won't come towards you since you're out of his range. Spells like fire strike can then be used to kill him.

The warlord is also prone to flinching. By attacking him and walking west, he will stop attacking you once you have reached far enough west. If you use a Ranged or Magic attack here, the warlord will start running back east. If you run towards him and start attacking him again, he will come back to you. Run west again before he is able to reach you, and repeat the process.

Once you kill the warlord and take the orbs, head back to the village and return them to King Bolren to complete the quest.