I'm from Walker Books and am going to answer some questions about the Power of Five website.
When you purchase your copy of Nightrise from Watertone's in the UK, it features a limted edition sticker with a code which will give access to a secret area: www.powerof5.co.uk/nightrise
It's possible that the 10-digit code could be cracked but I couldn't possibly comment
If you sign up for the Snakehead extract, you will be sent an email in June or July with instructions on where you can get it. I've read it - and it's brilliant!
There's lots of cool stuff on the site - including a live web chat with Anthony Horowitz - so I hope you like it. Happy to hear any comments!