The Ocean of Osyria (Hardy Boys)

After rescuing Jackpot, a kidnapped prize-winning racehorse, Frank and Joe are stunned to return to Bayport and discover that the Department of International Security has arrested their best friend, Chet Morton, for stealing a priceless art treasure! The Hardy Boys decide the only way to clear the friend is to journey to the Middle East and find the Ocean of Osyria themselves!