The Lion Guard are seen running to a hill, with Kion saying that Anga has spotted the next moja kwa moja stone over it. Before reaching it, though, they hear a strange sound coming nearby. Anga takes them over the hill, revealing the sound to be water from a nearby ocean, which Makini remembers from the last time she went to the Tree of Life. Kion worriedly asks Anga if the next moja kwa moja stone is in the middle of the ocean, which Anga denies, saying that the stone is at the top of the hill of the peninsula in front of them. Relieved, the Guard begin to move forward.
Bunga rushes ahead to jump into the beach, though the waves pull back, causing him to crash into the sand before he is swallowed by a wave. The Guard rush over to help Bunga, only to find him playing with a pink fish that Ono realizes is a dolphin. After dropping Bunga at the beach, the dolphin presents herself as Lumba-Lumba and begins talking about her life in the ocean, believing that she was born to swim and have fun. After thanking her for saving Bunga, Kion and the Guard decide to go on ahead as Beshte and Lumba-Lumba warmly exchange goodbyes with each other.
Anga informs Makini of a nearby patch of tuliza, much to Makini's relief, since her stash had just run out. Before crossing a nearby land bridge, an elderly civet stops the Guard, warning them about dangerous dragons up ahead. Not really believing dragons to exist, the Guard ignore the warnings and press on despite the civet's objections. At the beach, Fuli asks a somber Kion if he is okay, who only responds to wanting to find the moja kwa moja stone and move on, feeling they have been delayed enough today. Makini then leaves the group to fetch Tuliza from a patch nearby.
Suddenly, a large lizard named Ora approaches the group before attacking them, claiming they shouldn't have come, with Ono recognizing him as a komodo dragon. At that point, Makini returns before dropping the Tuliza in horror as she takes the scene in front of her. Though Ono warns that komodo dragons have venomous bites, Bunga tackles the dragon, unafraid due to his natural immunity to venom. Soon after, two other dragons, friends of Ora, join the frey. Now out of patience, Kion orders Bunga to get behind him before using the Roar of the Elders to blast the dragons away.
However, Fuli quickly realizes something is wrong as Kion continues to roar, blasting away the ocean in his anger before Fuli is able to stop him. Seeing the wasteland in front of them, Kion realizes he lost control of the Roar again. As Makini runs to grab some tuliza for him, the waters suddenly return in the form of a tidal wave. While Anga saves Makini, the rest of the Guard but Ono are caught in the waters. After the waves calm down, Kion is left in shock at the destruction he caused. Anga then reveals the waters have buried the land bridge, leaving them stuck on an island Kion created.
Realizing he needs tuliza, Kion asks Makini for some, though they soon realize the waves washed them all away. Soon after, the Guard hears Lumba-Lumba on the beach, having been carried ashore by the waves. Though willing to help, Kion is unable to come up with a plan to help Lumba-Lumba, guilt-ridden and pained by his scar. After Fuli reassures him, Kion puts her in charge until he recovers. Fuli sends Ono and Anga with Makini to find the moja kwa moja stone as well as Tuliza. Unable to drag Lumba-Lumba to the ocean, the Guard decides to dig a trench, hoping to bring the water to her.
Beshte and Bunga manage to dig the trench, but the water fails to reach Lumba-Lumba. Fuli reassures a pained Kion that Makini will return soon. In the jungle, Makini finds Tuliza for Kion as Anga keeps watch over the moja kwa moja stone. Suddenly, Ono spots what he thinks to be a dragon, though Anga reveals it's just more rocks. Makini comforts Ono, believing Kion blasted all the dragons away. Back at the beach, the Guard are still helping to fill the trench. Suddenly, the waves bring Ora and his friends back to the beach, who surround the Lion Guard, planning to eat Lumba-Lumba.
Meanwhile, Makini finds and activates the moja kwa moja stone. Ono then remembers the next landmark: a cliff with a tall tree on it, behind which the sun sets. Anga quickly finds the cliff, though noting they won't reach it so long as they're stuck on the island. Suddenly, Anga notices the dragons attacking the others. Back at the beach, the Lion Guard begin fighting the dragons, with Lumba-Lumba at one point helping Bunga save Kion. During the fight, Bunga defeats Ora by spraying him with his stink while Anga and Ono blind all three dragons with seaweed, allowing the Guard to defeat them.
After giving Kion tuliza, Makini tells him they need to leave the island in order to get to the next landmark. Facing the dragons, Kion appears ready to use the Roar before running to the other side of the beach to roar at the waters, parting the waves and creating a bridge. The Roar carries the waters ashore, returning Lumba-Lumba to the ocean. Kion stops roaring long enough to tell the others to move, allowing them to cross the bridge as Kion holds the waves up. After crossing, Kion drops the waves on the dragons behind them. Now safe, Kion asks about the next moja kwa moja stone.
While making their way to the cliff, they come across the elderly civet from earlier, admitting he had been right before telling him they've gotten rid of the dragons. Soon after, Lumba-Lumba thanks the Guard for saving her before bidding them farewell as they continue their journey to the Tree of Life. Meanwhile, the waves carry Ora to the beach, where he comes across Makucha and Chuluun, who have been watching him. Makucha invites Ora to join their quest of revenge against the Lion Guard, noting they could use someone like him. Liking the sound of Makcuha's plan, Ora agrees to join in.