The Resistance Underground Base, sometimes known as New Wartwood, formerly known as the Plantar Family Tunnels, is a catacomb of tunnels underneath the Plantar Farm in Wartwood. During the absence of Anne and the Plantars in Amphibia, it became the headquarters for the Wartwood Resistance following King Andrias beginning his plans for conquering Earth while preparing his Frobot military force.
Background[]
While putting together a family shrub, Anne grows bored as she finds the Plantar family history boring. Hop Pop runs out of glue and goes to the store to get more. Afterwards, Anne, Sprig, and Polly discover a secret passage that leads to several rooms under the house that reveal that some of their ancestors were incredible people, such as a scientist, a warrior, and a treasure seeker, the latter of whom was an honorary Plantar. The group solves puzzles and traps and manage to make it back just in time for Hop Pop, and a glued-on Loggle, to return.
After King Andrias began turning Amphibia into a wasteland as result of his plan to invade Earth for weeks. Sasha discovered the catacombs (likely from Loggle) and led the citizens of Wartwood to expand the tunnels, renovating it into an underground rebellion headquarters.
Following their return to Amphibia, Anne and the Plantars are shocked to see the world in disarray. They immediately flee back to Wartwood, which was destroyed and they are attacked by a giant mind-controlled centipede. However, they are rescued by the Wartwood Resistance, specifically Wally, Mrs. Croaker, and an unusually buff Loggle. Sasha reveals herself, having formed the resistance since Anne and the Plantars left, and reveals that they used the Plantar family catacombs as their base of operations. Everyone celebrates Anne and the Plantars' return and Sasha opts to have Anne take command, despite her reluctance. Grime privately questions Sasha's decision to give up command to Anne, but she tells him that it is "complicated".
The resistance's first mission with Anne taking the lead is to destroy the Collar factory where mind control necklaces are being produced, but it quickly becomes apparent that Sasha is better prepared for the job than Anne, who keeps making various mistakes throughout the day. They finally manage to find the factory, which is surrounded by a spiky gorge. Rather than do the obvious such as using a rope to get across, Anne has everyone stack on top of each other and make a bridge. The plan fails, but Sasha uses her skills to save everyone in the nick of time. At that moment, a giant snake with a mind control collar comes up and attacks the group. Anne tries to direct their attacks, but everyone gets swallowed whole.
Anne begs Sasha to take control, but she refuses as the last time she took control, she nearly ruined their friendship with her selfishness. Anne allows herself to be swallowed, urging Sasha to take control once again and direct everyone to widen themselves in the snake's throat so that it can cough them out. They break off its collar and free the snake where it slithers away, and proceed to blow up the factory. Anne finally convinces Sasha to take command again as she is better at it and she does so; Sasha agrees to take the lead but assures Anne that leading the resistance is a partnership. Anne is happy to be back with Sasha and furthermore is confident that they will rescue Marcy. She becomes very annoyed, however, when Hop Pop points out that Anne lost her shoe again.
After Tritonio Espada's Merry Band has been merged with the resistance, Sasha shows Anne and Sprig what Hop Pop discovered while he tried to find the bathroom. He found a door with the letter P, but it was locked. Then Hop Pop gets the book warning about the Calamity Box, and it goes through a slot which unlocks the door, revealing a room which belonged to the founder of the Plantar family, Leif. Sprig finds a red letter in the room, only to discover it was blank, leaving it a mystery to be solved at another time.
During the battle of Los Angeles, California, Sprig reads the letter while wearing Mr. X's glasses to see the ink. In a flashback, Leif wrote the letter to King Andrias before her death.