You made the right choice! It seems that everyone here has either seen or heard of Luke. You are close to the end, this may be the last leg of your trek.

A kindly molemaid told you, "I believe that Luke headed to Castle Marl, located in the lake southeast of Redwall Abbey."
A burly badger spoke soundly, "Luke, ah yes, briliant warrior. He went off to find Mokkan when he learned that Mokkan had been to Vilu's favorite port."

An old gray squirrel commented, "Seems like just yesterday that he passed through here. When I heard he had died I wondered what scum had slain him, and hoped that he got to Vilu first. Maybe he went out to sea, or perhaps he took the old south trail, but what if........