How to Avoid Certain Death- Tom Clempson

Charlie and Sarah are BORED. They live in the middle of nowhere with their dull grandparents who refuse to let them do anything exciting. But one day, adventure comes knocking when their grandparents are captured by the most terrifying pirate of all time - Vladimir Death Pirate. Charlie and Sarah launch an immediate rescue mission, setting sail to find their grandparents... in a bathtub!