The Lake Mystery - Marvin Dana

When an old miser dies, he leaves behind valuable gold. Naturally, many people want it. But the miser has not made it easy, hiding the gold with cryptic clues. Saxe, the son of a former music student of the miser, leads the charge to find it along with some old friends before time runs out and the money goes to the miser's blood relatives. But when an evil engineer tries to sneak in and find the gold for himself, Saxe and his crew must try to find the gold while evading the engineer. Who will find the gold first?. (Campbell Schelp)