Lost! is the first part of the ninth episode of Arthur season 2. Lost! aired on December 8, 1997. It aired with the episode "The Short, Quick Summer".
After school, Arthur is supposed to take the bus to the public pool for his swimming lesson, but he falls asleep on the bus and misses his stop. Then Arthur ends up at the edge of town but luckily, the bus driver helps him find his way home for free