Sword of Destiny

This book is the first in a series that involves the youthful Merlin on the planet Xann where he meets Asgard, the Keeper of the Universe. In exchange for his help he will have possession of the sword Excalibur to combat evil in The Known Universe. As part of Asgard's team Merlin will have seven lives and (potentially) seven gruesome deaths. This leads to many dangerous missions, including one to the planet Earth and in particular castle Camelot.