Hare and tortoise approach when Merrion (amateur) and Arnold (Scotland Yard) argue their way through the disappearance of a birdlover, whose will provides the motive for his murder when it outs. Merrion's imagination is bolstered up with facts dug up by Arnold, and, though repetitious in spots, the story is one that will appeal to followers of this combination, who like mysteries carefully and honestly unravelled.