This is the third in a series based on the utterly implausible premise that two modern-day kids find a frozen tyrannosaurus egg which hatches and the T-Rex becomes their friend. The book opens in a highly confusing fashion, jumping from the Amazon jungle, to Russia, to America. The most inappropriate part, though, is the level of violence. In the opening scene the T-Rex kills two men while protecting the hidden city of Eldorado. One of the men is bitten in half. Then the king of Eldorado tells T-Rex that he deserves a reward, so go ahead and eat the two dead men. I don't know why anyone would let a child read this book.