Just when T-Shirt thinks he's rid himself of one bossy bag, another rears her head. Tabatha Bag, sister of Tallulah Bag,. manipulates kindly Captain Cockle into letting her take up residence in his lighthouse, where she promptly throws him out.

The captain calls on Sally SImpkins for help and together the two attempt to expel Tabatha using the mystical Pearls of Wisdom, but Tabatha, having tricked T-Shirt into giving her the power she needs to rival Tallulah's magic, scatters the Pearls across the world. Sally must now find them if they are to stand a chance of defeating the new and less-than-improved T-Bag...