Wart stumbles upon Merlyn's home by 'accident', while he's wandering through the woods chasing a hawk for Kay. When he sees Merlyn's cabin in the woods, he knocks on the door and enters. Initially, he thinks that Merlyn is nothing more than a crazy old hermit, but then he comes to understand that he is actually very wise. The result of the encounter is that Merlyn realizes who Wart really is and declares that he is the tutor that Sir Ector has been looking for, for his sons. He goes with Wart back to the castle.
The Once and Future King