Take young, pretty people, put them in an exotic locale, stick in a few bad guys, have the two lead characters find romance after a couple of heavy breathing scenes, create the flimsiest of plots, then work out a happy ending for everybody (other than the three or four who get murdered, of course) That's the classic (and successful) format of the Harlequin Romance. It's not very good but then it's not very bad either, like most of the little yellow pocket books. And the location stuff in Budapest is especially interesting, even if they didn't use the wonderful old train station (designed by Gustave Eifel) or show the city's famous thermal baths.