The travellers(Horty, Fenna, and Springald) arrived back at Redwall near the time of the Harvest Moon. Right? The first sentence of the epilogue states "Ten seasons have passed since the night of the harvest moon." Okay, so it would be spring, right? Later in the epilogue, it says that Horty arrived with his Salamandastron hares, and that they would stay until after the Harvest Feast. This is a huge slip-up! The Harvest Feast wouldn't be in spring; it would be in autumn. And I seriously doubt that the Salamandastron hares would stay at the abbey for two seasons.