The doorway

In the first book the teenagers are drawn into a doorway into another world. During this time they are nearly killed by an exploding bomb. But instead they are endowed with super powers. Unfortunately, the powers are not enough when Wendy gets stung by a giant scorpion. In this book Brainy and Thumper must find special berries that will keep Wendy from dying. When they only find a single berry where they were told they would be they realize that they must go into the city. A city occupied by nocturnal beings who would gladly feast on their flesh. Now they will have to use every bit of power they have just to stay alive.