Showing White Night by Jim Butcher

A series of apparent suicides rings alarm bells with the police. And before he knows it Harry Dresden, professional wizard, is hired to investigate. At the first crime scene he finds an unmistakable magical taint - and a message specially designed for him, referencing the killing of witches.



Harry is desperate to hunt down his tormentor and halt the killings, but instead finds evidence implicating his half-brother, Thomas. To Harry, this just doesn’t add up, so he must add clearing his brother’s name to his expanding list.



Something that didn’t make the list is subtlety, and Harry’s search attracts the attention of the White Court of vampires … Soon, whichever way he turns, he faces a power struggle that will render him outnumbered, outclassed and dangerously susceptible to temptation. And if he screws up, his friends will die.