What is the main plot and ending of ranger's apprentice ruins of gorlan?

Ruins of Gorlan is the first step in Will's Ranger training, spanning from the time he was chosen by his master Halt to a short span in the future. As Will learns the basics of his new trade, he and Halt eventually go to the annual Ranger gathering where they learn that the Kalkara (beasts created by Morgarath) are on the hunt once again. Halt, Will, and his former apprentice Gilan track the Kalkara across the Solitary Plain, eventually splitting up--Will leaving to ride back to Castle Redmont for help from the Baron and Battlemaster. He returns with the two to find Halt in the Ruins of Gorlan; the two parties fight, the men loosing the battle, but the Kalkara are eventually defeated by Will shooting a flaming arrow at the extremely flammable beasts. The book ends with Halt revealing what he knows about Will's father and mother (his father an ordinary soldier who saved Halt's life and his mother a farm wife who died in childbirth, which brought Halt to take Will to Castle Redmont as the son of a hero), all of which had been a mystery to the orphaned boy.