In Vincent's secret hideout, Vicnent is rather bored while Mia and Paula are crying over a romantic drama movie. Mia slips up and mentions Mo, Paula wondering who he is. The television set breaks, and Vincent attempts to fix it. Paula excuses herself to go to the bathroom, while Mia looks at some illustrations of Mo in her book. Vincent calls Mia out on having a crush on Mo, which Mia denies. Paula returns, and asks about Mo. Vincent seems jealous of how Mia talks about Mo, which Paula comments about as she and Mia head outside for a moment. Mia assures Paula that both Vincent and Mo are just her friends, before heading back into the shed with the excuse of needing to talk to Vincent alone as her bracelet starts glowing.
Arriving in Centopia, Yuko, Mo, King Raynor and Queen Mayla are examining a map of Centopia, revealing how much the situation has worsened since Mia's last visit. Phuddle excitedly tells the group that there are only two more pieces of the trumptus left to find, and Mia tells the group the latest riddle, sending them off to search for one of them. Elsewhere, the Pans are having trouble because their territory has dried out. While the king is initially reluctant to seek out help from the elves due to their ancient rules of not being seen by them, he soon realizes they don't have many other options, and decide it is time to break those ancient traditions.
Mia and her friends arrive at a place where Yuko and Mo used to swim when they were younger, which has completely dried out. Onchao senses the trumptus piece, but isn't sure where it is. A group of unicorns walk over, the elves commenting on not having seen any in a while. With no water for the unicorns to drink, the unicorns are about to leave, when Mia decides to offer some water from her water shooter for the unicorns to drink. She convinces Yuko and Mo to do the same, and they continue their search.
At the elves' castle, the king of the Pans approaches Raynor and Mayla, while Phuddle tries to listen in on their conversation. Raynor agrees to let the king of the Pans stay with them, despite Phuddle protesting that it's a bad idea. In the meantime, Mia and the others are having trouble locating the trumptus piece, when Yuko gets the feeling that they're being watched. Some dark elves appear, and the group must improvise using whatever they can find since they already used up the water in their water shooters for the unicorns to drink. Mia, Yuko and Mo follow the dark elves, while Onchao is told to stay hidden until the group returns.
At the castle, the Pans arrive, and Raynor finds that the king of the Pans invited his whole village. Meanwhile, using the telescope Phuddle made, Mo discovers where Panthea is keeping all the unicorns, discovering that all the captured unicorns are still alive, albeit missing their horns, including Lyria. They want to save the unicorns, but realize that they're unable to do so at the moment. Mia tells them to keep this a secret, so Onchao does not get captured in an attempt to save his mother. The elves head back to find Onchao, deciding that they must find the last two pieces of the trumptus before they can help the captured unicorns.
Back at the castle, some of the Pans are unintentionally causing trouble for Raynor, Mayla and Phuddle with their antics. Mia, Yuko and Mo return to where they left Onchao, and continue searching for the trumptus piece. Mia hurts her hand, and Mo heals the cut with a unicorn tear. The tear lands on a clam, causing it to open. Mia finally realizes what the last part of the riddle meant, and that the trumptus piece must be inside one of the clams. With dark elves approaching, they must figure out which one it is quickly. Onchao makes a guess, but it turns out to be empty. Onchao then locates the trumptus piece in the clam right next to the other one, and the group take it with them and leave.
At the castle, Phuddle is delighted to find that he was right about it being a bad idea to let the other Pans come stay with them. When Mia and the others return, King Raynor asks Onchao to use his powers to restore the Pans' habitat so they can all go home. Onchao quickly brings life back to the plants in the area, allowing the Pans to return to their own habitat. Mia is determined to save the other unicorns soon, and with only one trumptus piece left to find, it won't be long before they can defeat Panthea.
Returning to her own world, Mia admits to Vincent that he was right about her being interested in Mo. Paula comes back in and asks how things are going, when Vincent fixes the television. Sensing an awkward tension, Paula asks if she should leave, to which both Vincent and Mia quickly tell her to stay.
