Anne and the Plantars are putting together a diorama for the Plantar Family Shrub (which Anne equates to a Family Tree). Sprig and Polly are bored while Hop Pop excitedly tells them about their family members such as Great Aunt Gertrude, who was a tiller, Second Cousin Alfred, who was "the king" of single tier irrigation systems, and ancestor Polli Ana who was a turnip farmer. Anne lacks interest, but Hop Pop explains that she does not need to be related to be considered a Plantar and that it should matter to her. When they run out of glue, Hop Pop leaves to go to the store, but tells the kids not to do anything until he gets back. While messing around, Sprig finds a button on one of their portraits that opens a hidden passage way in the fireplace. Anne, Sprig and Polly decide to venture down into the tunnel to see where it leads.
While venturing down under the house, Hop Pop has a mini adventure of his own trying to get glue from the Grub & Go and accidentally gets coated in piles of glue. Anne, Sprig and Polly find a hidden lab that belonged to Skip Plantar, a farmer and scientist who conducted crazy experiments. Sprig accidentally releases a pumpkin monster, but he traps it back in its cage and they fall through the floor. They end up in an armory that they learned was owned by Polli Ana who was a fierce warrior. Sprig once again pulls a lever and starts up Polli Ana's intense training simulator which Polly manages to get through with little to no effort.
Anne, Sprig and Polly end up in a room full of games which they learned belonged to Emma the Newt, an honorary Plantar who traveled the world collecting treasures. They activate a trap, but Anne is able to solve the puzzle and the trio escape the room. Hop Pop comes back home, without the glue, just in time to see the kids exit through the grandfather clock. They happily tell Hop Pop about the secret rooms in the house and how their ancestors were the the "most amazing warrior scientist farmers ever". Excited about the rooms, Hop Pop decides to venture in to see them, with Loggle stuck to his back by the glue. When the two scream in horror over the traps, the kids happily run in to help them.
- Brenda Song as Anne Boonchuy
- Justin Felbinger as Sprig Plantar
- Amanda Leighton as Polly Plantar
- Bill Farmer as Hop Pop Plantar
- Brian Maillard as Leopold Loggle
- “Anne this is based on nothing at all, but I'm almost certain that game will rot your brain!”
- ―Hop Pop Planter
- Anne: "Oh wow this looks unsafe. We have to got down there!"
- Sprig: "There could be treasure."
- Polly: "Or dead bodies! Let's do it!"
- ―After finding secret passage.
- Slacker Stackers is clearly a reference to Tetris.
- Later episodes would imply that Hop Pop may or may not have known about his family's more adventurous history.