Phineas and Ferb Season 4 Episode 7 - Sidetracked Episode Title: Sidetracked Episode Description: Agent P teams up with a former partner, a human agent named Lyla, to stop a hijacked train running along the US/Canadian border. In a past mission, they had a falling out, so Agent P must decide whether or not he can trust Lyla and her unique sense of logic to get them through the mission, defeat Doofenshmirtz and save the train's passengers and Canada's national treasure - a moose named Albert.