What adventure did Dorothy and her companions experience on their journey through the forest?

In Chapter Six, the woods grew deeper and more frightening. They heard many noises. A large lion burst from the trees and pushed the Tin Woodman and the Scarecrow over. He lunged for Toto but Dorothy, "heedless of danger" and filled with worry for her dog, leapt at the lion and slapped his nose hard, admonishing him not to bite Toto.

The Cowardly Lion stopped and apologized and explained that he was a coward. He did not know why, but all the animals expected him to be King of Beasts, afraid of nothing. Therefore, to keep his cowardice secret, he roared loudly at anything in his path to scare it away. He also asked if he could join their party in order to ask Oz for courage, and they agreed. Toto and the Lion eventually became good friends.