I am an Ann Cleeves latecomer, who discovered her through her first "Shetland" based novel, Raven Black, and have since become an Ann addict.
This, the second in her Shetland series has, in my opinion, outshone even the fantastic "Raven Black".
I wont go into a lengthy synopsis of "White Nights", as reading some of them can act as spoilers. All I will say is if you like your crime fiction in the old style ( Christie, Sayers etc..), but modern and up to speed with what is happening in other areas of crime fiction, then I think you will love this book. But I would read "Raven Black" first, as it happens to support a few of the relationships in "White Nights".
It is worth the price just to observe Ms Cleeves' descriptions of the islands, the communities, the hidden secrets that abound in isolated regions and above all the quirky characters who form the line up off these terrific yarns.