Kerry Greenwood 
Stormbringer ll: Lightning Nest [EPUB ebook] 

The heroes of THE RAT AND THE RAVEN have returned to the University, but they are restless. They don t fit in any more. Swart is told dreadful news by his father, and at the same time a petitioner comes on foot from far away, begging the wise people of the University for help against an enemy who wields lightning as a weapon. So it is time for Bran to gather his group again: the giant Mill the Hill, the dangerous twins Aethelflaed, the cowardly Dismas who can open any lock if he is scared enough, and Bran’s beautiful, strange lover Scathe, a transmitting empath. They must find the Lightning Nest a Tesla construct, and disable it. Harder things will also be asked of them before the end.