Wondering how to defeat Scar, Makini and the Lion Guard find a secret tunnel deep inside their lair. According to paintings of the past that depict the original guard led by Askari, the secret to defeating great evil is hidden inside. Along the way, each member of the guard is put through a dangerous test to prove their worthiness. At the end of their journey, they realize that Askari’s original Lion Guard was the secret, and by going through their tests they discover that they together, as the current Lion Guard, are the force that will defeat Scar.