When Zecora falls ill with a deadly sickness, it falls to the Doctor, Twilight, and Fluttershy to find a cure in her ancestral homeland Zebrica. All the while dodging the twisted machinations of an old foe from the Doctor's past.
After the harrowing events of "Traveller," the Doctor is forced into having some downtime in Ponyville while the TARDIS rests. Meanwhile, Twilight goes to confide in her beloved mentor, but ends up learning far more than she expected.