Superman Vol. 1 (1939-1986; 2006-2011) / Adventures of Superman Vol. 1 (1986-2006) #688

Plot

Mon-El's role as Superman's stand-in for Metropolis is threatened by a sudden and mysterious power loss. How can he be the hero he needs to be without any special abilities? Meanwhile the Guardian and his Science Police go to the rescue of a missing member of the Legion of Superheroes. And who is the spy within the Science Police ranks?