My oldest son, nearly six years old, loves these Jack Russell: Dog Detective books. Our library in Kansas had them all; our libraries here in Virginia have none of them. Luckily we've found a few at our local second-hand book shop. This was Book 6 (we've previously read 1, 4, and 7). This is one of the Australian things that's invaded our lives (along with Jessica Watson's blog, Mary Poppins books, and my wife's reading the "Specials" book series). When my son listens to Jack Russell books, he has a constant, irrepressible smile. That alone is worth a good rating.
Rating: 6 out of 7 giant inflatable monkeys.