|Roots of Evil|
|Air date||Apr 4, 2012 (USA)|
|Written by||Len Uhley|
|Directed by||John Delaney|
|Story by||Todd Garfield and Jeremy Corray|
|Supervising director||Steven E. Gordon|
Maahox's Haggarium-producing plant-life causes havoc on Arus. Allura's Voltron pilot duties are interfering with her royal responsibilities. Daniel struggles to hide a secret that threatens his standing in the team.
Maahox creates seeds filled with Haggarium, and secretly sends them to the planet Arus. Meanwhile, Allura is having more trouble combining her duties as princess with her duties as a member of Voltron Force. Later, the seeds have taken root and are attacking the cadets and the civilians. Allura comes face-to-face with the now grown treacherous tree that's taken over a farm and has to make an important decision about her future. She must choose between becoming Queen of Arus and helping her people or remaining the Blue Lion pilot as a member of Voltron Force.
Meanwhile, the cadets, minus Vince, battle the poisonous tree on foot, but soon Larmina finds out that Daniel is infected by the Haggarium and they keep it a secret from the team. Allura decides she needs to serve as Queen of Arus, and thus turns over piloting the Blue Lion officially to Larmina.