Nope I've not heard of them. What's it about?

The Divide is a magical place on a mountain ridge that separates two river systems - the watershed.
Felix visits Costa Rica with his parents. This will probably be their last holiday together as Felix is very sick and does not have long to live. He straddles The Divide, passes out, and wakes up to find himself in another dimension. In this place fabulous creatures are real, and Felix is the mythical being. He is befriended by Betony, a spirited tangle-child, and together they set out to find a cure for his illness, and the way back home.
In a land where magic is everyday, and science is the stuff of myth, Felix himself becomes the quarry of Snakeweed. Snakeweed is a japegrin with big ideas; ruthless and unscrupulous. He uses devil-hyenas - known as sinistroms - to do his dirty work, and sees Felix's world as an untapped market for magic.
Despite numerous obstacles Felix and Betony obstinately pursue their quest in this strange world, and are helped by many different creatures. But Felix is running out of time, and he knows it.
this is what the web site says. thay are soooo good!!!!
i love them!!!!!