It is really remarkable that an author who has been writing exciting mysteries involving teen age girls for so long has kept so up to date on her modern young people. Although this is typical of the many she has written, it is still readable and something is happening every minute. Her chapters end with ""cliff-hangers"" (""little did she know...."") which, even if in the cliche class, do help suspense melodramatically. The heroine, on a New Jersey shore, finds an octant, a marine instrument that ante-dates the sextant, only to lose and find it several times when she tries to trace its story and value. Not to be compared with many of her earlier and better planned and executed stories, particularly those with historical backgrounds.