Suspenseful fun and hilarious read!  Could not put this book down and I did not see that twist I never saw coming.  If you read book 3 who know that Alvin planted a little trap for dear Hiccup and his friends.  Now Hiccup is on a quest to find the only cure which happens to be The-Vegetable-That-No-One-Dares-Name aka a Potato.  But who has this cure?  Well a Viking named Norbert the Nutjob.  Now doesn’t that just sound like a friendly name. 4.5/5 Stars & “B+”.