"Tempering her praise of the book, Sturch thought that "Mr Fleming works often on the edge of flippancy, rather in the spirit of a highbrow", although overall she felt that the novel "contains passages which for sheer excitement have not been surpassed by any modern writer of this kind".The reviewer for "The Daily Telegraph" felt that "the book is continually exciting, whether it takes us into the heart of Harlem or describes an underwater swim in shark-infested waters; and it is more entertaining because Mr Fleming does not take it all too seriously himself".