A short chapter book in traditional style about a family of blackbirds who unwittingly raise a cuckoo's egg among their brood, and the dire consequences on the other chicks when it hatches out. Although blackbirds are usually very good parents, neither Danny nor Daisy notice that they're raising a cuckoo, and it's left to their young son Brains to try to save the family from disaster. This dramatic story has some sad moments including some tragedies for the bird family, but it also contains an uplifting message about family ties, loyalty, friendship with those who are different, and overcoming obstacles. It's also gently educational about how the natural life of birds in the wild.