The Hardy Boys, Frank and Joe Hardy, are fictional teenage brothers and amateur detectives. Frank is eighteen (sixteen in earlier versions), and Joe is seventeen (fifteen in earlier versions). They live in the city of Bayport on Barmet Bay with their father, detective Fenton Hardy; their mother, Laura Hardy; and their Aunt Gertrude. The brothers attend high school in Bayport, where they are in the same grade, but school is rarely mentioned in the books and never hinders their solving of mysteries. In the older stories, the Boys' mysteries are often linked to their father's confidential cases. He sometimes requests their assistance, while at other times they stumble upon relevant villains and incidents. In the "Undercover Brothers" series (2005-2012), the Hardys are members of and receive cases from American Teens Against Crime. The Hardy Boys are sometimes assisted in solving mysteries by their friends Chet Morton, Phil Cohen, Biff Hooper, Jerry Gilroy, and Tony Prito; and, less frequently, by their platonic girlfriends Callie Shaw and Iola Morton (Chet's sister).