Grand Theft Dragon

White Wolf Mountain
Talk to the scout at Barbarian Village. When he asks if King Roald has sent you to him, just choose the option that says "yes" (even if you didn't see the king). After that, a cutscene automatically plays showing White Wolf Mountain surrounded by guards. He tells you to sneak into the lower basement of the mountain and destroy all the orbs. The lower basement can be accessed through a tunnel complex outside of the Ice Queen's lair.

The Tunnels
Follow the tunnel complex where it leads. Although there are many other tunnels but the rest are blocked by boulders. At the middle of the tunnel, the tunnel begins to darken and if you try lighting a candle or a lantern a mystical force will put it out. Then if you look closely on your minimap before the whole tunnel becomes dark, you will see a fork in the path. And those two paths will also split later on. After you choose a path, a few paces and the whole thing becomes pitch black. Right-click just about everywhere and look for examine 'wall'. If there are walls at each side then you can go straight but at least after every 5-10 squares start examining! Do so until the screen becomes brighter. Don't worry all paths that split will join again.

The Hideout
Get to the hideout and find an underground castle fortress. A cutscene appears and shows that several guards are guarding three 'portal orbs'. Then you see a huge cage the size of Lumbridge at the corner of the chamber. Follow the route up the second floor and get to the balcony. Kill all the archers there. Then, man the triple ballista at the third floor which is accessible from the end of the second floor balcony. Use the triple ballista to accurately fire one arrow at each portal orb. If you miss or accidentally fire two at one orb then you can go back to the second floor and pick up the 'missiles', then use the 'missiles' on the ballista until it is full. After the orbs explode into pieces, the dragon cage will be unlocked. Go back down and run past all 9 lvl 51 guards in multicombat area to the cage. Ride a dragon and fly. Just left click on any dragon to 'mount' a dragon and it'll automatically bash through the wall and into Varrock (don't worry you can ride it for real later).

The Campsite
Once you mounted the dragon it will automatically fly to Varrock and into Varrock palace. When you land in the courtyard, dismount your dragon and go talk to the king. He asks you about the dragon and if your helping out in the war. What war? Talk to him again and he tells you that dracomancers are leading an army of half human half lizards into Varrock and all other major cities around Gielinor. Looks like you'll have to go see the scout again. Go talk to the scout and tell him about what to do with the dragon. He'll say that a squadron of dragonriders are heading to Falador through the wilderness. He'll say you'll need your dragon to intercept them and at least bring back a prisoner for interrogation. Go get your dragon at the castle unless you flew it there. Then fly your dragon to the wilderness near black knights castle. Once there keep going north until you see a small camp with dragons all around. Land your dragon near black knights castle and proceed on foot to the camp.

Sneak in
Walk to the camp but not directly to it but around it at a non lit place. Don't worry the dragons are all asleep.

Sabotage
Find a knife near the tall tent and pick it up. Then, use the knife with the dragons to cut the rope the dragons are tied to.

Steal
Go in one of the tents which has a red circle with a white cross in the middle. The occupant is asleep so you don't have to fight him. Go to the desk and steal the vial of liquid.

Capture
Capture one of the high ranked dracomancers there which is asleep. Pick him up and he will take up your sword and shield slots. Bring him back to your dragon.

Escape
Go back to your dragon and fly back to the scout. Task complete

Rendezvous
Go to Varrock and talk to the king. Tell him that the attack on Falador has been dealt with and that Falador is safe for now. He thanks you but brings you some bad news. Unfortunately the whole dracomancer invasion of Misthalin, Asgarnia, Morytania, Piscatoris and Kandarin has been ordered to land in Port Sarim! After hearing the news you suddenly jumped so high that you flew out of the castle and into the general store in Al Kharid! Before you jumped out you found a letter in your bag saying to meet up with an agent in Port Sarim. Go to Port Sarim.

The Task Force
When you arrive in Port Sarim, dozens of soldiers litter the docks. Go around Port Sarim to meet with a few spies behind rocks. Talk with the spy whose wearing a purple hat thingy. He tells you that a dispatch of dracomancers are leading the invasion through three points: Karamja, Mos Le'Harmless and Ardougne. He says that he cant get to his ship because soldiers have invaded the whole port. Another spy says there's something to do with the sabotage in white wolf mountain that's causing the invasion force to divert its attacks to Misthalin... whoops!

Underground Breach
After talking go south of Port Sarim and you'll see an opening in the ground. Go back and talk to the spy and tell him to follow you down the hole. When you climb down the hole. A guard and a miner are mining there. Kill them both and pick up the pickaxe that the miner drops unless you already have one. Mine at the rocks and a cutscene will appear. you dig a tunnel into Port Sarim jail which is guarded by two guards. After the cutscene finishes, pick up the iron rod on the table nearby and use it on any of the jail cells. You will bang the rod on the jail doors. It will attract the guards to come into the jail. Kill them both without letting any of them to escape or any of the soldiers outside see or you'll be spotted and thrown into the river lum and wash up near Varrock. When they're both dead sneak outside to the pier and go to the very last boat there. There the SS Watch-a-ma-call-it lies in the port. The spies will board it and sail south to Mos Le'Harmless.

The Attack
Go back to Varrock castle to claim your dragon. When you ride it the king wishes you good luck and you ride off to Mos Le'Harmless. When you reach there on your dragon, 5 battleships along with several smaller ones are docked there. Looks like a battle! Go to the far east of the island and there you see a division of the Misthalin Special Forces pinned down by lizard dudes. Pursue the cold blooded noobs. Click your summoning button and press the dragon breath button. Then click the cannon and your dragon will blow it up. Two dragons tail you after you torch the draco-cannon. Fly up at full speed until you lose both dragons, then dive and engage the lizards. Have an adamant x-bow or better and use the free aim mode to take down the dragonriders. Once they are both taken down, return to the spies and tell them they have secures the island and got word that the other task forces have secured Karamja and Ardougne. But suddenly, another scout says that Varrock is under siege. Make haste for Varrock and don't stop for no runeburger or scimitar-soda until you reach the castle. (Although a scimitar-soda sounds nice)

The Ambush
When you reach the castle, the courtyard is littered with dead guards. Proceed to the dining room and there you see the king tied to his throne and a couple of dracomancers. One of them is the leader of the lizard dudes. Kill his guard which is quite an easy fight. After that the leader says some conquer the world words and throws some snakes at you. Kill the lvl 5 snakes and talk to the leader again. He says he'll summon his 'pets' to take you for 'a walk'. He takes out a small box and raises it up into the air. After it flashes, all of a sudden two huge Taipan snakes come crashing through the door. They are both lvl 146 and can poison you as much as 26 damage! Bring as many antipoisons and prayer pots. Use the chivalry and piety prayers if you have them or just turn on protect from melee. I suggest you bring decent food such as swordfish or sharks. Once you kill both of them, the leader tells you to fight him. He is quite impossible to defeat. Then, you thought of something. What does that potion you found at the campsite do? Whatever it does use it on him and cross fingers. All of a sudden, he starts to fall to the ground and he turns into a normal human. Looks like the potion saved your life. Although he has turned mortal he is still a threat, so kill him. Untie the king and he congratulates you. He then gives you your reward and offers you a place in the Varrock Knights in the Guardians of Misthalin. You will then accept it.

Congratulations! Quest Complete.

Rewards

 * 50,000 gp
 * New Dragonrider skill introduced
 * New transportation introduced
 * New Dragon Shop open in Falador
 * Access to Varrock Knights armoury