Every time Ultimate Magus is mentioned on a forum, someone adds that Versatile Spellcaster would be great with it. I do not see how.
Versatile Spellcaster (Races of the Dragon, p. 101):
You can use two spell slots of the same level to cast a spell you know that is one level higher.
Does a Wizard know any spells?
He has clearly some in his spell book, he has some prepared, but what does he know?
