Picking up after Quint and Dirk's Hero Quest, the Last Kids are happily reunited--but quickly faced with a monstrous new mission. Inside an other-dimensional fortress, the evil Thrull, alongside a vile new villain, is carrying out a sinister plan. Jack, Quint, June and Dirk must make their own plans to infiltrate the stronghold before Thrull gets any closer to completing the mysterious Tower, a structure that could ultimately spell doom for this dimension....

"The last kids may have escaped the forbidden fortress by the skin of their teeth, but there isn't much to celebrate. Thrull has what he needs to complete the Tower, Rezzoch will most certainly come to Earth, and the world as they know it will cease to exist. Except Jack's Cosmic Hand is now even more powerful than he realized, and it might just be able to stop the inevitable from happening. To get the answers he seeks, he'll need to travel farther...