Barney Pot is the nephew of Billy Pot, the dragon keeper of Spit Fyre by appointment.
Barney Pot was told by Aunt Zelda to go deliver Septimus Heap the Living SafeCharm. When Barney reached Septimus, Septimus wouldn't accept the SafeCharm because of his experience of being given the Questing Stone. Septimus didn't believe he was only going to give him a SafeCharm, so he left, but not before Barney finally yelled "It's from Aunt Zelda!". It was still too late, for Septimus was already high in the air. Barney tried going back to Aunt Zelda to return the SafeCharm, and encountered Merrin Meredith while looking for the Keeper. Merrin took the SafeCharm from Barney, as he knew that the thing that Barney was holding was important per what Barney revealed, thus Merrin refused to give it back and kept it for himself. Hence, Barney didn't just fail to deliver the SafeCharm to Septimus but he also lost it to Merrin. Barney told Aunt Zelda what happened by sending a note, and Aunt Zelda recounted it to Marcia Overstrand. Barney and Aunt Zelda then searched for Merrin, found him and questioned him; Merrin told them he let the jinnee that was in the SafeCharm go, and Barney and Aunt Zelda would have to go find a "stupid giant banana".
Barney was encountered by Lucy Gringe and by Alfrun Snorrelssen in the Palace. Barney was the door opener in the moment but when his uncle Billy Pot told him to go to bed, his time of being the door opener ended.