A collection of three Rich and Stan mysteries which have been published separately as "Right diamond, wrong pocket", "The mystery of the missing Roman coins," and "Right data, wrong scientist." Right diamond, wrong pocket Rich and Stan have won a trip on a luxury yacht but they soon get caught up in a mystery when someone has stolen a diamond One of the super rich on board the yacht is also a super thief. Can they find out the clues they need to catch them before it is lost for ever? The mystery of the missing Roman coins Rich and Stan are investigating the theft of some Roman coins in the museum. Who stole them? Was it the Roman skeleton? Can they find out who the thief was before the thief gets them This time it is historical Right data, wrong scientist Rich is plummeted straight into an adventure when he foils an armed robbery. The villains are displeased with this and he has to leave quickly before they get him. Rich and Stan get invited to a science experiment in an old castle looking for alien life. What could be safer than looking for aliens? Unfortunately the castle has a more dangerous criminal than the one they left behind. Will they survive to discover the truth?