The Penny Treasure is a fictional British book which appeared in the episode iFence.
Sam was assigned to read it for school, which she had no intention of doing. After Sam and Freddie argued about Sam's reading habits, he bet her that she wouldn't be able to read the book cover-to-cover. (The bet pushed Sam to actually read the book.)
The loser of the bet would have to perform the "Ushe" (this meant that the loser would have to stick a hose down his/her pants and turn it on, making it look like they had wet their pants). In the end, Sam actually does read the book and wins the bet, so Freddie pays his debt.
To prove that she'd actually read it, which Freddie didn't believe, Freddie tested her on the content - we discover Jarvis, probably the main character, ventures into a cave and finds the "key of tranquility", which was four feet from Gideon's grave.
- The book that Sam was holding was actually a copy of Harry Potter and the Deathly Hallows, with a fake cover slipped over it.