Sam's home town of Topside is full of pigeons. What's wrong with that? All towns are full of pigeons, right? Yes, but these birds are bigger and meaner than your average crumb pecker and they're acting strangely, too, upsetting the locals and causing havoc.Can Sam and his faithful chum Nina work out what - or who - is behind these pesky pigeons? And will Sam's super loud voice be enough to prevent a bad-bird disaster?