While I was ranting about getting an expensive Telekinesis spell, I failed to notice that one of the spell scrolls I picked up in that room with the "trash" piles was a TK scroll. Oops! (And now my two former Sorcerers are Archmages.)
P. S.: I'd read that Corlagon's Lich was a real toughie to fight, but I discovered that Liches, Ghosts, and all sorts of Oozes are very susceptible to electric spells. Who knew? It was amusing to see poor ol' Corlagon cowering in his boots, trying to flee, while both Wizards attacked him with Lightning Bolt. He couldn't get a single attack in.