Karen White, her sister Laura and brother Tim were all born with a gift - the ability to open doorways between worlds. It's an ability she has long suppressed, partly due to the warnings (and accompanying beatings) given to her by her adoptive father as well as the memories of a haunting figure, The Grey Man, who seems associated with the siblings use of their powers.

But all this is many years behind her, as is any contact with her power-sharing brother and sister. Karen is now a middle-aged and soon to be divorced mother of teenage Michael.

When the Grey Man starts to appear in her son's life she restarts contact with her sister Laura and heads, along with her son, into the alternate world Laura where has been living. But this can never be a final escape as the Grey Man and the organisation that controls him are committed to tracking them down.

And when they are contacted by the long lost Tim, they are drawn closer to this mysterious organisation and the other world where it is located.

Robert Charles Wilson has to be one of my favourite current writers. I picked this book up as a bit of a treat for myself, having decided I just did not want to wait until his new book. And thankfully, once again, he has not let me down.

The thing I have enjoyed with RCW's writing over the years is that he seems to approach his brand of sf from a totally different angle to most current writers. This is not hard sf in anyway excepting his concepts. He takes sf plot devices to deliver the his characters into a situation, and then the rest of the book explores how they react to their situation.

The most common sf device in his books is transportation to an alternate world, and this is once again in evidence here. But despite his re-treading ground he has visited before, this is certainly not stale.

Wilson writes excellent fiction, and this book certainly helps cement his reputation. Now I need to go order the latest book.