Root Beer Guy works a boring job during the day and tries to write mystery stories at night. But his life is about to change when he witnesses Finn & Jake kidnapping Princess Bubblegum! There's only one problem: no one believes Root Beer Guy...

Finn and Jake decide it's time for Finn to get a new sword. Finn reluctantly buys a grass sword from a mysterious old man, but the sword turns out to be cursed! And unfortunately for our hero, all sales are final.