Frankfurt to Wiesbaden

There's a deceptively light social comedy style about this that manages to almost entirely mask the horrifying naivete, self-deception, broken trust and shallow propriety that fuel the wonderfully slight plot. As Ian McEwan does these days, with a great deal more portentousness and pomp, the faintest shift of events has consequences of hinted-at remorseless carnage. The climactic, almost apocalyptic horse-ride into the forest has left me actually quite shaken. You can probably get this for 99p on Amazon.