Ride the Robot Train is a mission in Ratchet & Clank. While exploring Metropolis, Ratchet and Clank found a train station with a parked robot train, guarded by the blarg, who were transporting an infobot.
Be careful of the train's movements, as you will maintain forward momentum while jumping from platform to platform as the train swerves left and right. This goes double for dodging the blarg commanders' rockets, as there is no available cover and little space to dodge. After reaching the front car and defeating all four commanders, the train will park and the infobot will leave. Follow it as a mine layer will try and block your path, though it will not go very far. After destroying the robot and some nearby crates, head right and take a passage on your left to find the infobot, containing coordinates to planet Eudora. After this, as you escort yourself down the elevator, take note of a small area to the right with some crates. Glide into it before taking the elevator all the way down.