Rakkety Tam
Penguin Putnam has posted the following summary of Rakkety Tam in their catalogue:

A gripping new Redwall adventure.

A threatening presence has arrived on the shores of the peaceful Mossflower Valley, heading for Redwall Abbey. Gulo the Savage has a vendetta to fulfil and with his crew of vermin he is going to reclaim the magical Walking Stone. Two warrior squirrels Wild Doogy Plumm and Rakkety Tam MacBurl head up the brave animals defending their Abbey. An epic tale in the Redwall saga full of courage and comradeship.

Barnes & Noble has also posted a new summary for Rakkety Tam:

The most captivating Redwall novel yet!

There has never been a Redwall hero quite like Rakkety Tam, the roguish Highlander squirrel who sets off for Mossflower Wood on a mercenary errand and loses his heart to the charms of Redwall Abbey. And there's never been a villain quite like Gulo the Savage: a vicious beast-eating wolverine who descends upon the Abbey in search of a relic called the Walking Stone. Readers will cheer at the return of the Long Patrol, the antics of a renegade vole thief, and the emergence of a new champion to wield the sword of Martin.

As fans of Brian Jacques and the bestselling Redwall series know, the adventures just keep getting bigger and better.

Rakkety Tam is slated for a September US release and an October release in the UK.

Stay tuned to The Newsline for more details.

(Special thanks to Mackinsie and Keyla for bringing the afore-mentioned summaries to my attention.)