In the Lair of the Mountain Beast by James Moloney
And this comment will clearly demonstrate how far behind my reading list is! I just purchased volume 5 of this series last week, and I am only now getting around to commenting about book 4.
I have been reading James Moloney for years. His early books focussed on adolescent relationships and the importance of families. But a couple years ago he wrote his first fantasy novel, The Book of Lies, and I loved it.
Soon after The Book of Lies, Moloney commenced a scifi adventure series for upper primary/lower secondary, The Doomsday Rats. Each book is short, full of excitement, complete within itself, but leaves you wanting the next installment now!
As with many scifi novels, a summary sounds trite and unappealing, but here goes anyway. The idea of the series is that an evil genius has drugged the adult population and manipulated them to his will. This tyrant has an army of genetically modified beasts who act as enforcers. However, the good guys are a group of kids who live underground in the sewers, fighting evil whenever and wherever they can. As the children grow, they can no longer fit into the sewers and must take their chances above ground.
In this installment of the story, some of the children discover there is an antidote to the drug in a hidden valley in the mountains. So they leave the security of the sewers and head for the hills. Along the way they encounter some adults who also exist outside Malig Tumora’s control. And naturally they are followed to the secret hiding place.
To say any more would spoil the story, so find the series for yourself and enjoy them all.