S1·E32 To the New World

All the trains evacuate to Area V, and the Robot Trains block the tunnel that connects to the Fountain Plaza. But Duke's duplicates penetrate and come through the tunnel, endangering everyone in Area V. Then Duke arrives to Area V just in time. It turns out Becky has unlocked Duke while everyone evacuated. Only thing that can stop Duke's duplicates is the energy coming from the Alpha Train.