There are a lot of blazes, and there are ghast spawners above them. All of those spawners were primed, because they've been slowly working their way up the dragon. The plan is to fall back and shoot things from far away.
Ten blazes in between
The plan has some problems. There's a blaze in his space. There are so many ghasts. At one point there are something like ten blazes between them. One of them digs what he means to be a little tunnel up, and it turns into something else. The one with the Infinity bow takes on the ghasts and gets very good at it. A viewer sums it up: this place is horrible. Yes, it is.
Somewhere in the middle comes the question, have you got the wool yet? You shut your mouth. They think a lot of the noise is coming from inside the dragon. It might be hollow.
The important box
They can see the box now, above the head. To get to it they need to go straight up, and between them they have wood but no cobble, so it's quartz for building blocks. There's a spawner below the box, and ghast spawners on the dragon's horns. Out on the skull is actually kind of safe, since it's a lot of obsidian and the ghasts seem confused.
The trouble is the bridge. If the ghasts blow up what you're standing on, you're done. One of them gets blown off when they take out the ground underneath him, and has to eat chicken like his life depends on it while the other brings water. Arrows run out at the worst moment, one arrow left, so 29 more get handed over. One spawner on the side goes down. The blaze spawner and the magma cube spawner sit right on the box.
Not the wool
He gets there by not stopping: run in, hit it, run away. Inside the box is a Grand Treasure Chest, and it's nether wart and all kinds of crazy potion stuff, plus some dragon's breath. Not the wool. That leaves the mouth, or maybe somewhere through the dragon itself.
An emerald room in his head
There's a line of blazes leading into the dragon's eye, and inside it they find an emerald. It's just an emerald room in his head, and the other eye connects to the same room. One of them is out of arrows again.
Water goes down off the front of the face to put out the lava below, and one of them jumps. From down there it looks like you can go into the mouth. The other wants to repair his gear before they do that, since there may be a lot more level inside. So that's where they stop, with the mouth next. A fantastic place to end.
