Give an account of everything that happened from the time the heard waves of howling till Gandalf set the pine trees on fire.

Here is an overview of ch.6:

Bilbo has escaped the goblins but he is still lost and has no clue where he is. He sees that he is on the east side of the mountains, at the edge of the Land Beyond. Bilbo fears that his friends are lost and he thinks of returning to find them. Fortunately, he finds the group and surprises them with his presence‹he is able to sneak upon them wearing the ring. He tells the story of Gollum though he neglects mentioning the ring. Inside of the Goblin tunnels, the group has lost track of several days and though they are disoriented, they must continue forward. After all, the goblins are intent upon avenging the death of Great Goblin.

Gandalf urges the group ahead and they encounter a pack of wolves. They can climb up a few nearby trees but they are surrounded. The wolves and goblins are allies and as it turns out, the wolves are waiting in this forest-glade because they have planned a joint-attack with the goblins. Of course, the wolves cannot carry out their attack on the town because the goblins have not shown up at the appointed hour‹and this is because they are mourning their leader and looking for the dwarves.

Gandalf knows that he must do something and so he starts a fire in the midst of the wolves, attracting the attention of the Lord of the Eagles. Goblins arrive on the scene to mock the pained wolves and in a clever move, they burn fires around the trees in order to trap the dwarves. The Lord of the Eagles arrives and carries Gandalf away, just in time, and other birds come and save the dwarves and Bilbo. And so, the chapter ends with Bilbo lodged in a safe place, sleeping soundly.