What to read after High Rhulain?

Summary (part 1 of 2): The story follows the journey of a young ottermaid named Tiria Wildlough, born and raised in Redwall Abbey. Tiria was the daughter of Banjon Wildlough, the Skipper of otters. Martin the Warrior and High Queen Rhulain Wildlough appeared to her in a dream, saying the otters of Green Isle needed her assistance and leadership. After deciphering and scouring the Abbey for many clues with Old Quelt, Sister Snowdrop, Abbess Lycian, Brinty, Tribsy, and Girry, Tiria learned through another dream that she had to leave on her own, so she headed to Log-a-Log Urfa's encampment along with her father and Brink Greyspoke. Meanwhile, the ruling wildcat of Green Isle, Riggu Felis, and his sons Jeefra and Pitru attempted to kill the osprey Pandion Piketalon and failed, leaving Felis' face permanently disfigured. Pandion flew away from Green Isle and lost his way and found himself in Mossflower Woods. He was captured by a gang of rats, but was later rescued from Groffgut by Redwallers; the merciful Redwallers allow the gang to live, but Groffgut vows to slay the one who humiliated him in combat--Brinty. Pandion is brought to Redwall and healed. After seeing the iron barb in his beak inflicted on him by Felis, Tiria vows to kill the one who did this with their own weapon, and she takes the barb. Leatho Shellhound, a rebel outlaw, leads various attacks against the wildcats with other otterclans, which causes the otters to have to relocate to Holt Summerdell after their cave is discovered. But the otters are now hopeful as the High Queen Rhulain has been prophesied to come to Green Isle by Zillo the Bard. Urfa takes Tiria to Cuthbert Blanedale Frunk, a Long Patrol hare with mental problems brought on by the death of his daughter Petunia. He then takes her to Salamandastron, which is now ruled by Lord Mandoral Highpeak; there she receives the High Rhulain armor that was made by Urthwyte the Mighty for her predecessor, and a sling made for her by Lord Mandoral Highpeak. Along with the osprey, Pandion Piketalon, as well as Colour Sergeant O'Cragg, Master Sergeant Bann, Capt. Raphael Granden, Corporal Drubblewick, Lt. Sagetip, Quartle, Portan and a score and a half of the Long Patrol, she sails to Green Isle in Frunk's ship, the Purloined Petunia. Riggu Felis's son Pitru has become Fortress Commander of Green Isle while his father tries to hunt the rebel otters. Pitru tries to usurp his father's position in his absence, but fails. Afterwards, the two continue to plot against one another. While Felis is hunting the otters, he finds their hiding place in the coves, but the otters manage to escape and hide.