Spirits of past arcane masters are bound to this well-equipped laboratory. Their aid allows you to refocus your magic for other purposes.
Wondrous Item 425,000 gp
When you spend 24 hours studying in this laboratory, you can replace one arcane power as if you had gained a level and retrained. After you use this property, you can’t use it again until you gain a level.
Published in Adventurer's Vault 2, page(s) 79.