Air date: September 11th, 2020 (UK); September 1st, 2020 (US)
Safety inspectors are coming to the island to make sure everything is running well. All the engines will have to be checked over and can continue with their regular work. Then, there will be an emergency drill. The engine closest to Rocky is supposed to collect him, and the other engines need to head to Knapford Station.
Everything runs smoothly until it is time for Rocky to be collected. Rebecca, James, and Percy all go to collect Rocky, not knowing who is closest. Percy overruns a red signal, causing all three engines to derail. At Knapford, Sir Topham Hatt hears the news. Emily immediately goes to fetch Rocky to help Percy, James, and Rebecca.
Meanwhile, Gordon is forced to go a different route with the express, and all the road vehicles have to take a detour too since the accident happened at a level crossing. All the traffic causes a road bridge to start cracking. Emily calls out to Bertie, who takes all the vehicles off the bridge.
But Gordon still does not know this. He goes under the bridge and is frozen with fear as it is about to collapse. Luckily, Emily brings Rocky to hold the bridge up so Gordon can move. The safety inspectors are impressed with Emily for preventing a nasty accident, and so is Sir Topham Hatt. He has Emily made the official Sodor safety engine—and finally given the number 12.
This episode contains examples of:
- The Cameo: In an example of a non-sentient vehicle character, the Sodor Post Van is seen during the traffic scene.
- A Day in the Limelight: Emily serves as the main character, as her quick-thinking is on full display.
- Freeze-Frame Bonus: Thomas' whistle budges up and down when he blows it, like how Nitrogen Studios animated the whistles.
- Wham Episode: Emily is not only made the official Sodor safety engine, but she is also given the number 12 after being in the series for 17 years.
