Power of five series - what age?

[clemetteattlee]

A friend's son is about to turn 11 and is a fan of Anthony Horowitz's. I was thinking of getting him a copy of the first book in the Power of Five series but wondered if he was too young. Has anyone's DC read it?

ds(now 14) has - he says the themes are quite dark but no more so than Alex Rider,so if he has read those should be ok.

Great, thank you.