Having no one to help her with her problems, a widowed mouse visits the rats whose former imprisonment in a laboratory made them wise and long lived.

While on a rescue mission, a few daring mice journey below to the sewers to an evil world populated by rats who peel mice before eating them and worship the Dark Lord.

As a result of an experiment stripping the fur from his tail, Harold the squirrel finds himself homeless and mistaken for a rat on the unfamiliar streets of New York City.

Althought Felina the cat queen is gone, the subway tunnels are still dangerous, not only because of Hopper's rogue brother Pup and his arachnid companion Hacklemesh, but also due to a secret Firren has been hiding that worries her more than the disappearance of her daughter, Hope. Includes a bonus story, ATLANTIA RISING: How it All Began.

Hopper escapes a pet shop and soon finds himself in the tangle of Brooklyn's transit tunnels in Atlantia, a utopian rat civilization where Hopper is treated as a royal guest until a multi-generational and multi-species battle breaks out and Hopper learns terrible, extraordinary secrets, including one about his destiny.

"Something terrible is happening in the skies! Rats are eating the MOON! There's only ONE hero for the job, a bold and fearsome beast bioengineered in a secret lab to be the moon's savior and Earth's last hope! And that hero is... a cat. A cat who will be blasted into space! Accompanied by the imperious Moon Queen and LOZ 4000, a toenail clipping robot, the First Cat in Space journeys across a fantastic lunar landscape in a quest to save the world....

"... the beady-eyed, green-tongued witch Truda Hangnail spreads evil along her path to succeed Queen Bluebell, enlisting the kingdom's rats and shrinking the good witches of Wadingburn to pave her way to the throne. Luckily, a sweet-natured orphan named Loobly is witness to Truda's evil spells and sets off to fetch help."--Jacket flap. When the quill writes "Go Go Go" frantically on the wall, and the House of the Ancient Crones heaves Gracie Gillypot...

Tansy, a young hedgehog living at Redwall Abbey, attempts to solve the riddle of the missing pearls while at the same time the evil marten, Mad Eyes, desires them for himself.