Locked in a standoff with Susie over who will say sorry first, Mildred runs away to the woods and befriends a ghost. Will one of the McAllister sisters give in and apologize before the townsfolk run Mildred out of town?

When Oscar isn't invited to Alexa's birthday party, Mortimer tries to make him feel better by telling him about a similar time in his life. Ever the glowworm, Oscar sneaks back in time to help a young Mortimer overcome the sad experience.

After discovering that young Mortimer doesn't have any friends, Oscar helps him start a new club on campus. But the monsters are forced to hide their newfound friendship from the school – and Stuart.