Searching for the god Pan is sort of a family tradition for Grover Underwood. His father was a Searcher and so was his grandfather. Searchers are satyrs who have been specially authorized by the Council of Cloven Elders to go in search of the god. Being the god of nature and the wilderness, Pan holds a special place of importance for satyrs. Pan went missing centuries ago, yet satyrs refuse to believe the rumors that their god is dead.
The problem is, no one has ever successfully found Pan. Even worse, those who have gone off on this quest never return. However, Percy has confidence in his friend and believes that if anyone can succeed in locating the elusive god, it is Grover.
In The Lightning Thief, Grover remains unlicensed, although he continues to stay vigilant for signs of Pan and other searchers. When Grover and Percy happen to come across Medusa's lair, Grover discovers the fate of his Uncle Ferdinand, who also was a Seeker. Ferdinand has been turned into a stone statue like all the others who have been unfortunate enough to glance at Medusa's hideous face. In the end, upon their return from the quest for the lightning bolt, Grover is finally granted his Searchers license. The subsequent books in this series include further stories of Grover's quixotic search for Pan.