Plot

When Twilight Sparkle and her friends come down with bizarre conditions, a mysterious zebra is blamed and pursued.

Twilight finds out that the rest of Ponyville are frightened of the mysterious zebra Zecora who lives in the Everfree Forest, and insists their fears are unfounded. An encouraged Apple Bloom goes off to follow Zecora to her home, and the others quickly follow once they notice her missing. They recover Apple Bloom just as she enters a field of blue flowers, where Zecora warns them off. The next day, Twilight and her friends find themselves suffering from strange problems, leading the others to conclude that Zecora has cursed them. They find Apple Bloom missing again, and assume that Zecora took her. They race to Zecora's hut and confront her, only to find her and Apple Bloom making a potion to cure them of the afflictions, which were caused by the Poison Joke flowers they had stepped in the day before. Once cured, Twilight and her friends convince the townsfolk to be more trusting of Zecora.

Twilight Sparkle is surprised when all of Ponyville shutters its doors when a Zebra named Zecora comes into town. Her friends explain that Zecora lives in the Everfree Forest. Though noone's taken time to talk to the Zebra, many of them assume she does evil things.

Twilight refuses to believe this, when she and the others notice Applebloom is missing! They follow her trail to the Everfree forest, finding her on the edge of a field of blue flowers. Zecora is also there, and warns the ponies to 'beware!'

All of them return home and go to sleep, but wake up the next day with strange afflictions:

-Twilight Sparkle's unicorn horn has softened

-Pinkie Pie's tongue has swollen up, and all she can do is spit

-Rainbow Dash's wings are inverted, and she is unable to fly properly.

-Rarity's hair has grown incredibly long, hindering her sight and movement.

-Applejack has shrunk to a small size

-Fluttershy's voice is deeper and male-sounding

Almost everyone assumes that Zecora has placed a curse on them. As they discuss this, Applebloom sneaks away, but is tagged along by Applejack, who hides in her hair. As Applebloom nears the Everfree Forest, Applebloom comes out of hiding, and demands her sister go back to Ponyville. However, Applebloom refuses, and places her 'little' sister on a tree branch, before wandering back on her way to Zecora's.

Shortly afterwards, the others find Applejack, and continue on their way to Zecora's, where they see her working over a bubbling pot, and wondering just where Applebloom is.

The others then burst into her hut, assuming she is going to cook Applebloom, before Applebloom appears in the doorway, having returned from finding some ingredients for Zecora.

Both Applebloom and Zecora explain that the reason for the pony's afflictions, was due to their encounter with the field of blue flowers the previous day. The flower is called 'poison joke,' and Zecora was making a cure for them. However, not all of the ingredients she has will work, and she needs to get them from Ponyville.

The others help Zecora return to Ponyville, and show the others in town that they have nothing to fear. Eventually, the girls are returned to normal.