You know those two hobbits called Baggins? Their trips only came after naggings from Gandalf the wizard. They wandered through blizzard and mines, then they drank loads of flagons. Now, one found a ring of great power, and one found his way to a tower to bring down a Dark Lord, or perish in Mordor; a deed which caused Sauron to glower.
There’s sadness, adventure and mirth in the lands all around Middle Earth. Right in the middle’s what’s won with some riddles: a magical ring of great worth.
Now a saga is something quite serious, potentous, designed to quite weary us. A limerick’s light, reputedly trite, unsuited to epics imperious. So a story of hobbits, and wizards, and elves, and matters a saga digs down to and delves is no topic for limerick, it’s pointless to mimic. If you want such a tale you must write it yourselves!