Marjorie, left at a boarding school by her emigrating mother; plain Poppy, pushed into marriage with a mean-spirited aristocrat; Kate, despised by her father, but determined to prove herself; and man-mad Lily, who turns out to be the bravest of them all. That all of them are chosen to work undercover for the espionage unit at a beautiful stately home is a surprise, not least to them. At Eden Park they not only meet each other, but become involved with three unusual young men – Eugene, the seemingly feckless Irishman; Robert, Kate's brother; and dashing Scott, a master of disguise, and the undisputed favourite of the unit. While there is hardly time for romance before each is sent out into the field, there is just enough for passionate new relationships to form. Only Jack Ward, the mysterious spymaster, manages to remain aloof as he guides their destinies. The fact that they will look back on this time as having made them feel more exquisitely alive than ever before is not something they will know until much later.