Nancy Drew 60 (English, OHP transparencies, Carolyn Keene)

When she is told that a large inheritance from a Greek tycoon, meant for her friend Helen Nicholas, was stolen, Nancy agrees to find the culprit. A poisonous snake in a basket of apples and a strange symbol stamped on a rare Byzantine mask are clues in this mystery set in the beautiful and exotic country of Greece. These clues lead Nancy and her friends to a ring of art smugglers and to the secret of the Greek symbol.