There's a new Viking-themed promotion at the Krusty Krab, so SpongeBob is determined to find out everything there is to know about Vikings. And what better way to find out about Vikings than to talk to them himself? So SpongeBob writes a letter to the Vikings, and is surprised when they decide to pay a visit to the Krusty Krab to answer his questions in person. Mermaidman and Barnacleboy are having a book signing, but SpongeBob can't go because he has boating school. After some convincing, Patrick finally gets SpongeBob to take a bathroom break from class – a really long one – so they can go to the signing, and SpongeBob can just go back to class when he's done! But the day turns sour when SpongeBob becomes racked with guilt about ditching class.