Episode 5: Old Friends
Original Air Date: August 19, 2011
Episode Written by: Tab Murphy, Directed by: Yoshiharu Ashino and Sean Song
Article by: Purrsia

WB Summary:
Panthro finally joins the team, but his gruff demeanor intimidates Lion-O. Despite his best efforts, Panthro can't dissuade the Cats from following him on a mission to get Thundrillium to fuel the Thundertank. Plus, a mission leads Panthro to his old nemesis: Grune!
Purrsia's Synopsis:
Picking up shortly after the last episode left off, Panthro announces that his ThunderTank needs more Thundrillium. Gruff and tough, the old General wants to go alone but Lion-O insists on going as well. The group head off to the Cloud Peak Mine to get the fuel for the Tank.
At the mine, Grune is overseeing lizard workers who are mining the Thundrillium - a substance Grune calls the "lifeblood" of Mumm-Ra's army.
Meanwhile Panthro begrudgingly lets Lion-O and the other adult 'Cats tag along (the kittens and Snarf stay behind with the Tank), marveling that the crew has survived thus far without proper leadership. When Cheetara mentions how Claudus fought to the death to save Thundera, but Grune's treachery was overpowering, Panthro thinks back through his long history with his former friend.
Grune and Panthro were once inseparable, competing for title of General in Claudus's army. When the day arrives for Claudus to announce his General, neither gains the title. It is given to Lynx-O. Claudus explains that he wants his most experienced and best warriors kept together on a more important task - to seek out the Book of Omens. As the quest goes on, Grune starts to believe Claudus feared his ambition and sent him on a wild good chase to be rid of him. Perhaps sensing his true heart, Mumm-Ra beckons Grune who cannot resist following the old mummy's voice until he - with Panthro following in puzzlement behind him - reaches the pyramid. When Panthro doesn't join forces with Mumm-Ra and Grune to get the Sword of Omens, Panthro is disposed of (or so they thought!)
Now, the two old friends have a score to settle. But instead of staying to fight, Grune lets a machine - the Driller - do his fighting while he flees. Lion-O manages to fight the Driller off with some impressive sword play, but the Driller had weakened the mine and the whole mountain starts to crumble around them. Cheetara races back to grab some Thundrillium, and they all escape in time.
Convinced Lion-O is at least competent with the Sword, Panthro swears his loyalty to the young Lord BUT draw the line at letting him drive the ThunderTank.
Quotes:
"You're standing on my samoflange." - Panthro to Lion-O.
Panthro: You plan on becoming a lion?
Grune: No, I plan on becoming king.
"And remember, what you cannot earn can always be taken." - Grune's advice to young Tygra.
"You'll have my loyalty when you can show me you can do more with that Sword than just carry it around." - Panthro to Lino-O.
"Open it and I'll grant you the power you desire, the power you deserve!" - Mumm-Ra, coaxing Grune to release him from his sarcophogus.
"All those deaths and you're still not the king!" - Panthro to Grune.
Facts of Note:
It appears Mumm-Ra was perhaps trapped or imprisoned in his sarcophogus until Grune freed him.
Classic Compare/Contrast:
In the classic show, it was Jaga and Grune who were old friends until Grune betraoyed him. Here of course, it's Panthro and Grune that were once close only to have Panthro "come back from the dead" (figuratively anyway) to have it out with his former friend.
Otherwise, Thundrillium is still a major fuel source in this new series, just like in the original.