When a new army of predators seizes control of the Tree of Life, it's up to Kion to channel his Roar to drive out the bad guys.
At dawn, Makucha's Army is seen chasing three mountain goats across a field while Mama Binturong watches from a nearby tree. It doesn't take long for the Night Pride to arrive, wondering how the Army got into the Tree of Life without them knowing. Flying by, Ullu apologizes to Rani for her mistake, saying she dozed off. Seeing Baliyo yawn, Surak notes they're all tired, this being the fourth day in a row the Army has attacked at sunrise. The Lion Guard soon arrive, well-rested and ready to take on the Army. Under Kion's command, the Guard defeats the Army and sends them running.
After the battle, Rani compliments Kion as Bunga claims that Kion is back while lying on the leg of a seemingly annoyed Surak. Agreeing with Bunga, Nirmala states that Kion's healing is complete since the battle has proven he could be calm and focused. The rest of the Guard cheer at the good news, realizing they can now go back to the Pride Lands. Hearing this, Rani worriedly asks if this means they'll be leaving, right now. Kion, however, refuses to leave, noting that the Lion Guard swore to protect the Tree of Life during the day. Greatly relieved, Rani bids Kion and the Lion Guard farewell as she and the Night Pride go for their rest.
Noting that Kion is healed, Bunga asks if he'll use the Roar of the Elders again. Much to his surprise, though, Kion reveals he can't yet. Leaving Fuli in charge, Kion walks away from the group, saying there's something he has to do. Confused, Bunga shouts at Kion to explain himself, wondering why he doesn't use the Roar if he is healed already. Though Fuli gets him to come with the others on patrol, Bunga remains suspicious of Kion. At Cikha Escarpment, Kion meets with Askari, ready to continue his training with the Roar, with Askari saying he has already made great progress so far. However, Askari tells Kion that only one who is willing to give up the Roar completely can truly master it. Still, Kion insists he wants to give the Roar up, feeling he doesn't need it to lead the Guard. Understanding, Askari tells Kion he will soon learn all the Roar can do.
At a desert, as he tries to free a camel stuck in the sand, Bunga complains to the Guard about Kion, annoying them. Bunga's rash attitude upsets the camel, who promptly vomits on him as Ono explains that it is a nervous reflex. After freeing the camel, Bunga resumes ranting to the Guard, believing Kion's in trouble and he's just not telling them. Wanting answers, Bunga leaves to go ask Rani about Kion, believing she knows what is going on, as the rest of the Guard continue their patrol, glad to enjoy the silence now that Bunga has left the patrol.
Outside the mountain pass, the Army is seen arguing over their failed plan, all agreeing the Guard has gotten stronger with Kion. Discouraged, Chuluun admits she's close to giving up, though Mama Binturong silences her, saying she doesn't give up and neither do they. Saying things will be different from now on, Mama reveals she has brought reinforcements. As if on cue, Smun's Prickle arrives outside the pass, bringing the rest of Makucha's Leap and Ora's Bank alongside them. Now with a large army, Mama Binturong declares they will soon feast on all of the rare animals and get their revenge, saying the Tree of Life will be theirs.
Inside the Tree, Bunga starts asking around for Rani, causing Makini to rush over and quiet him, saying Rani is resting. Regardless, Rani wakes up and greets Bunga, who asks her about Kion's suspicious behavior. Though Rani doesn't know anything, Makini speculates Kion is still working on the Roar. Showing them a painting, Makini explains how Askari would go to Cikha Escarpment and practice the Roar, learning everything that it could do.
Thinking over all this, Rani has an epiphany and realizes she needs to talk to Kion in private. However, unable to shake Bunga, Rani allows him to come with her as well. At Cikha Escarpment, Askari teaches Kion about the Roar, saying it can be precise it he can control his emotions. Following Askari's instructions, Kion roars at a nearby pillar, lifting a rock into the air and breaking it. Impressed, Askari praises Kion for mastering the skill quickly, with Kion noting he had help learning to stay calm. Under Askari's tutelage, Kion channels the power of the Roar around the Escarpment's rocky terrain.
In a tree overlooking the pass, Ullu sees the large Army approaching. Before she can warn the Night Pride, though, she is captured by Mama Binturong, who orders the porcupines to watch over her. Luckily, Ullu scares them by turning her head all the way around, allowing her to escape. By this point, Rani and Bunga begin to climb up Cikha Escarpment, though the honey badger's antics soon start to annoy the Queen, causing her to pull what Bunga calls a Fuli face. Suddenly, they hear Kion roaring in the distance and, excited, run to the top of the cliffs and see something Un-Bunga-lievable.
Arriving at a field, Ullu finds and wakes the rest of the Night Pride, warning them about the Army. Taking charge, Surak orders Ullu to warn the Lion Guard while they get Queen Rani. By now, the rest of the Guard are seen walking through a forest when they hear a stampede, which Anga discovers is Makucha's Army, having already made its way past the mountain pass. As the Guard wonders why Ullu didn't warn them, the owl arrives and tells them the Night Pride is on its way. The Lion Guard start making their way to stop the Army, hoping the Night Pride can hold them off as they get there.
At this point, the Night Pride enters the Tree of Life looking for Rani, instead, they finding Makini, who tells them Rani went to look for Kion with Bunga. Suddenly, a boulder is placed at the entrance to the underground chamber, trapping everyone inside. With no one to stop them, the Army starts to chase animals all over as Mama Binturong declares that the Tree of Life now belongs to them. Arriving at the scene, the Guard sees all of the Army and resolves to get rid of them. Noting the Night Pride is missing, Anga soon spots the boulder at the entrance, realizing they're trapped inside the Tree of Life.
Thinking quickly, Fuli tells Anga to look for Kion and Bunga while the rest try to help as much as they can. At Cikha Escarpment, after seeing Kion lifting rocks into the air, Rani and Bunga reveal themselves and cheer for him, noting he has been practicing. At this point, Anga finds the trio, telling them of the Army's invasion and the Night Pride's capture. While Rani and Bunga follow Anga to help, Kion takes a moment to thank Askari, saying he is now ready before leaving. Meanwhile, the Lion Guard continues to fight the Army as the Night Pride struggles to move the boulder with Besthe's help.
Seeing Beshte moving the boulder, Mama Binturong sends Ora and the other dragons to stop him, cornering him. Suddenly, Anga swoops in and saves Beshte, bringing the others with her. Their presence angers Mama, who orders Makucha and Ora to go for Kion and Bunga. At a cliff overlooking the fight, Rani allows Kion to take care of things, saying she trusts him as he prepares to use the Roar. Hearing the thunder building up, Fuli worries about Kion using the Roar in front of so many animals, though Bunga tells her it's okay. While Ora worries about the Roar, Makucha tells him to act like a dragon.
Remembering Askari's teachings, Kion controls himself before using the Roar of the Elders, striking the Army's leaders with concentrated blasts that are heard by the Night Pride below. Channeling the Roar, Kion unleashes small twisters and rocks at the Army, at times even lifting Bunga and Beshte into the air and drops them against the enemy. After Rani reminds him the Night Pride is still trapped, Kion summons lightning to destroy the boulder, freeing them. With the power of the Roar, Kion defeats the Army as Rani and the rest of the Guard watch in awe, amazed by Kion's new powers.
Soon after, the Night Pride emerges from the Tree to find the predators scattered over the field, confusedly realizing that they've won. With the group back together, Fuli wonders what to do with the fallen Army. Stepping up, Kion offers to convince the predators to never attack the Tree of Life again. With Rani's permission, Kion uses the Roar to summon a larger twister that sucks up the Army and takes them far away. The Night Pride reunites with the others, with Baliyo regretting having missed out on the Roar as Makini rushes over to Kion, realizing he was working on the Roar.
Having achieved control of the Roar and his emotions, Nirmala declares Kion is fully healed. Rani thanks Kion for getting rid of the Army, though Kion notes it was the least he could do, considering he was the one that brought them into the Tree of Life. Having seen the full powers of the Roar for herself, Rani now understands why Queen Janna was so happy to have the Roar return to the Tree of Life. Noting that the Roar is now here, Rani proposes that Kion should stick around and remain at the Tree of Life instead of returning to the Pride Lands, leaving Kion and the rest of the Lion Guard stunned.