Trama

Thomas is jealous of those who get to pull coaches so jumps at the chance when Henry is sick, but ends up starting up unattached in his hurry.

Thomas has recently been grumbling about only being used to collect the coaches for the other engines, wanting to pull passenger trains as well. The other engines laugh, telling him he's too impatient and would be bound to leave something behind. Thomas is determined to get a chance to prove them wrong.

One night, Thomas and Henry are alone in the shed as Henry is ill. The workmen try their hardest to make him better but to no avail. The next morning, Henry feels just as bad as the previous night. He's due to take the first train of the day and Thomas is needed to get the coaches ready. Thomas starts to hope that he will be allowed to pull the train if Henry isn't able to. He excitedly leaves to fetch the coaches.

Thomas brings the coaches to the platform and is eager to run round in front. His driver does not let him, telling him to be patient. Soon, all the passengers are aboard and the coaches are ready to leave and there's still no sign of Henry, much to Thomas' excitement. The Fat Controller arrives to see what's going on and is told about Henry. He orders to find another engine and as Thomas is the only one available, he allows the tank engine to take the train.

Thomas, full of joy, quickly moves to the front of the coaches despite his driver again warning Thomas not to be impatient, but wait until everything is ready. For some unknown reason - either he's too impatient to wait, the driver has pulled a lever by mistake, or the crew have forgotten to couple him to the coaches - Thomas ends up leaving the station without the coaches and the passengers are very surprised and angry. The men in the signal box outside the station wave and shout, though Thomas thinks they're cheering.

Thomas sails along the line, thinking pulling coaches is easier than he was told. He keeps seeing people waving at him and assumes it's because he has never pulled a train before. Eventually, Thomas is stopped at a signal set to "danger". Thomas is angry at being stopped when he was sailing through nicely and blows his whistle, alerting the signalman who asks what Thomas is doing on this part of the line. Thomas explains he's pulling a train, but the signalman asks him where the coaches are. Thomas looks back and realizes he has left his train behind. He's very upset at his mistake and is ready to cry. The driver tells Thomas not to be upset and he reverses back to the station.

At the station, all the passengers are complaining to the Fat Controller about what happened, but when Thomas returns, they see how sorry he is and allow him to try again. This time, Thomas is properly coupled to the coaches and he gets the chance to really pull the train. But sometime later, the other engines begin to laugh at Thomas and remind him of his mistake, much to his annoyance.