Applejack has been asleep for a week, trapped in a strange recurring dream that neither medicine nor magic can wake her from. In desperation, her wife Rainbow Dash takes her to Zecora for help.
With Zecora's help, Rainbow Dash enters Applejack's dream to try to find the cause of it. They find that the farmpony is cursed, trapped in her own mind by a lie—a powerful one. To break the spell and wake her up, Rainbow Dash has to uncover Applejack's lie, and the truth behind it.
But what could Honesty herself be lying about, and why?