Púca: From old Celtic mythology. A shape-shifting spirit, benign but mischievous. Very fond of social outcasts.

Applejack and Apple Bloom return to their childhood farm to live with their brother, Everfree B. Mac, after their grandmother, Martini Pine Smith, passed away. However, they are shocked to learn that Mac has discovered a new friend: an invisible 7-foot draconequus he calls Discord.

Fearing for the mentality of her brother (and her credibility among the higher-ups), Applejack decides to have Mac committed to the local sanatorium. Things go awry when SHE is diagnosed as the psychopath.

However, not everypony is convince that Discord is just a figment of Mac's imagination. Take the journey into the world of Everfree B. Mac as he and his best friend overcome this incredible obstacle.

[spoiler]This is a crossover with film adaptation in 1950 starring Jimmy Stewart, Harvey, which was based off the 1944 stage play of the same name.[/spoiler]