This is probably the best episode of Season 1.
The premise of the episode is that time-space and thought are all the same thing. It beautifully explores the concept and lets the enterprise travel to a different reality.
Wesley is greatly used in this episode, as he is the only one paying attention to the Traveller. However, all the grown-ups just don’t care. By the end of the episode, Wesley is rewarded with a new rank as acting ensign.
The episode gives you the feeling that not all is lost and you look forward to the next adventure.