Readers on Amazon consider it readable at 3 - 7 Grade Level.
A popular method used by schools to measure a student reader’s ability is Lexile level or a Lexile Measure. The Lexile Level of Hardy Boys 30: The Wailing Siren Mystery is 700L .
Readers of age 8 - 12 years will enjoy Hardy Boys 30: The Wailing Siren Mystery .
Caught in their motorboat the Sleuth by a sudden storm at sea, Frank and Joe Hardy are relieved to see the lights of a yacht. But their SOS ignored. The shrill sound of a siren fills the night air and moments later a helicopter drops an object alongside the Sleuth: a wallet containing two thousand dollars! The next day, a truck carrying a shipment of high-powered rifles has been stolen. These two apparently unconnected events are clues in a tangle of mystery which turns out to be one of the detective brothers’ most exciting adventures. Read more