This could have been good. Really good in fact, but I found myself asking most of the way through, 'Where's the details?' It's not exactly a thick book and some proper details would have got it four stars. 
 The reason why I would only give it four was because aside from the lack of detail the plot was just silly. I read a series of books like this when I was younger that you might have heard of, Angels Unlimited (aka Agent Angel). They were amazing, some of my favourites as a kid and I'd read them over and over. This however has a very week plot, a main character that I find impossible to like and many stereotypical characters. 
 Riley is your typical whiny brat, when she dies I believe she spends some time in the Summerland, although no more than a couple of sentences in mentioned about that. Her sister, Ever, goes back to Earth and I couldn't help but wish I was joining her instead of being stuck with her bratty sister. 
 Anyway, the Radiant kid. So, hundreds and hundreds of years and no ghosts are able to get him to cross over. To no-one's surprise, Riley is able to do this. When I read about this I couldn't see how so many ghosts had failed where she succeeded. Cant see myself reading any more of these books but the younger YA readers might enjoy them.