LordTBT from this forum and head of the Redwall Wiki posted a fascinating article speculating about the existence of a 23rd Redwall book. If you remember when The Sable Quean was first published, there was an announcement of a character naming contest. The winner would have their character show up in a future Redwall book as their prize. Well, it turns out there was a winner, and the character didn't show up in The Rogue Crew. LordTBT did some major sleuthing, and came up with some interesting results.
I won't rehash what he found, as his article deserves to be read, so check it out and post what you think. While we must keep our expectations tempered, I think this gives us some hope for one more story.
http://redwall.wikia.com/wiki/User_b...ery_Deciphered