At the farm, Mia notices that one of the pigs, Gypsy, doesn't seem to have much of an appetite. Franca comes over to see Renzo, with Renzo explaining that she needs his help repairing something. Renzo leaves Mia in charge, assuring her that he believes she can handle looking after the animals for a while. Mia continues to wonder why Gypsy won't eat, and decides to call Mario, who is currently helping out at Violetta's ranch. Mario decides to leave early, but is momentarily delayed as Violetta falls off of her horse. After making sure she's okay, Mario leaves.
Coming to help Mia, Mario makes note of Gypsy's behaviour and is able to figure out what's going on. Mario helps deliver Gypsy's piglets, and Mia excuses herself to go inside for a bit when her bracelet begins to glow.
Mia arrives to find that Onchao is feeling sad because his father is not around. Mo shows up and asks about the latest riddle, and the group head to the palace, thinking it has something to do with the green fluid Rixel uses to control his animals. At the palace, Mia suggests that if they knew more about the potion, they could possibly make an antidote. Mayla mentions that they do know someone who could possibly help, but Raynor protests that he doesn't want the group heading back into the Blackwood Forest.
Mia recalls that she didn't actually see any ghost in the forest. Mo doesn't want to disobey his father again, and sends Mia, Yuko, Onchao and Phuddle off without him. Arriving at the entrance of the forest, the mysterious elf observes as they discuss their intention of reaching the heart of the forest. The mysterious elf comments that he must stop them from reaching it. Trying to find their way by going in the way opposite of the one shown on Phuddle's malfunctioning compass until it breaks, the group wonder where to go. Hearing the sound of a flute and recalling how it helped them reach their goal the last time, they try to follow it once more. However, this time, they instead find themselves led back to the entrance. Mia and the others decide to head back in, and when the flute plays again from the direction which they came from, the group decide to keep going in the opposite direction.
The mysterious elf drops a sleep thistle onto the path, which causes Phuddle to fall asleep. The group keeps going, Onchao carrying Phuddle, until they reach a large wall of vines. Unsure of how to keep going, they try to find a way to get the "ghost" to help them, Phuddle waking up at the mention of the ghost. Believing the group to be leaving, the mysterious elf comes out from his hiding spot. The group introduce themselves to the elf, who initially questions why they're there, before introducing himself as Simo, and revealing that he's trying to keep them away because his mother doesn't want visitors.
Simo manages to slip through the vines easily, giving Mia the clue needed to solve the riddle from her book. The group head through the vines without resistance, and reach the heart of the forest. Simo is amazed at Mia's ability to understand unicorns, as a trio of nature unicorns arrive. The unicorns ask Onchao if he is Ono's son, and Simo explains how these three unicorns are his only friends. Simo's mother shows up, and tries to get the group to leave. Simo tries to convince her to let them stay, and threatens to leave with them if she doesn't let them stay. Onchao catches the elf's attention, and Mia explains that Onchao is saying he doesn't want to come between her and Simo.
Mia shows the elf the vial of fluid and explains why they came, and the elf takes it to analyse it. Phuddle follows her inside to watch her work, and offers to help. While she is initially skeptical to letting Phuddle help, he makes a suggestion that she admits isn't a bad idea.
While waiting in a nearby tree, Yuko offers Simo a friendship ring. Simo is initially reluctant to accept it, but Yuko convinces him to take it. Tessandra and Phuddle finish their analysis, and reveals that she can make an antidote, but only if they can bring her some water from the Rainbow Spring, which can only be accessed with the unicorn king's crown. Mia realizes they must find the crown.
Raynor is not pleased that the group went into the Blackwood Forest again, but admits that he's glad Tessandra agreed to help them out. Mia must return to her own world, and arrives as Renzo and Franca return to the farm. Mario shows up carrying one of the piglets, and Renzo is surprised since he wasn't expecting Gypsy to give birth until next week.