The longest-running series of books to feature the Hardy Boys is the Hardy Boys Mystery Stories, sometimes also called the Hardy Boys Mysteries. The series ran from 1927 to 2005 and comprises 190 books. Some consider only the first 58 volumes of this series to be part of the Hardy Boys canon. The Hardy Boys also appeared in 127 volumes of the Casefiles series and are the heroes of the Undercover Brothers series. The Hardy Boys are largely successful because their adventures represent "a victory over anxiety". The series teaches readers that "although the world can be an out-of-control place, good "can" triumph over evil, that the worst problems can be solved if we each do our share and our best to help others."