Summer vacation holds little promise for Oliver who has just moved with his parents into a new home in a town where he knows no one. So when his grandmother suggests he join her on a tour of Great Britain, he quickly accepts.
Only later does he learn that most of the people on the tour are senior citizens, with the exception of two sisters, one of who shows signs of being a thief. Oliver and eighty year-old Mr. Hahn spend time together and the Scots bus driver turns out to be an ally. Oliver attains hero status when he thwarts a purse snatcher outside of York Cathedral.
By the time the Wonder World Tour ends, Olver has discovered that friends can be young or old and that friendship is forged in the most unexpected ways.