The main character in the short story, "The Liar" by Tobias Wolff is the liar. He's a young teenager who spins tales about his family for anyone who will listen. These fantasies are horrific stories of the capricious way fate and health has treated his family. Unfortunately they (the tales) are something that his mother a rock solid and honest person cannot deal with. In her efforts to find a resolution, she sends to a doctor hoping to cure him. What makes this somewhat dark tale worth the effort of reading is the plausibility of its characters and their genuine concern for each other. The boy knows his mom is hurt by his lies, but he cannot seem to help himself.
Surely something catastrophic has occurred to send his lies spiraling out of control, and we learn soon enough that he was the person to find the body of his father after he had succumbed to cancer. In addition he had to fight with the corpse as he struggled to get it upstairs to the bedroom so his mother would feel comfort in the fact that the father died peacefully in his own bed.