Books like Moonlight and Magic by Rachel Lindsay

Jane Berry a budding journalist, was, in looks, the image of Janey Belton, the famous and glamorous heiress. When she attends the swanky retirement party of a well known 'diva', she runs into her double, Janey Belton, who is due to go on a luxury Mediterranean cruise, full of VERY well heeled passengers. Janey convinces Jane to go in her place and Jane does so because: a) her boss at the tabloid paper she works at would love the idea of her attending a celebrity-full cruise 'under-cover' so to speak and b), Jane's father, an Insurance investigator, is pursuing a jewel thief that he believes will be one of the cruise passengers. Jane become close to a mysterious passenger, Stephen, who unbeknownst to her, actually owns the paper she works for. Her cover is blown by a glamourous passenger, with her sights and talons, set on landing Stephen - just when Jane had eliminated all passengers but two, as the possible jewel thief - and one of the two is Stephen himself.

First publish date: 1972