Anthony Horowitz 
I Know What You Did Last Wednesday 

There’s been a murder on a remote island … but the Diamond Brothers are on the case!When the Diamond Brothers receive an invitation to a school reunion on a remote Scottish island, things seem to be looking up. But Nick’s got a bad feeling, and it’s not indigestion. And when he meets their fellow guests, the feeling only gets worse – especially when they start dying in ever more bizarre ways!