The Magic May Return
by Larry Niven
Book 2 in the Magic Goes Away series (1981)
Publisher: Ace Books
A collection of short stories written by other fantasy and sci-fi authors. The stories describe adventures in a world where mana, the power that makes magic possible, is running out
Once there was unlimited magic, but reckless magicians have used up the mana, the power behind the magic. Larry Niven opens his world to the storytelling talents of Poul Anderson, Steven Barnes, Mildred Downey Broxon, and Dean Ing with stories that tap the hidden reserves of mana and uncover the forgotten places of power.