Samson and the Fireworks is the fifth episode of the twelfth season.
Samson arrives on the mainland with a load of empty trucks and his brake van Bradford in tow. On his way to the Blue Mountain Quarry, he meets Thomas hauling a load of fireworks. Samson mentions that he is scared of fireworks before continuing his journey. Not long afterwards, thick fog rolls in, resulting in Thomas, Gordon, Emily, and Rebecca nearly or accidentally crashing into each other due to being unable to see the Knapford signal gantry. Unaware that detonators are being placed to alert engines of upcoming signals by Cyril the Fogman on the Fat Controller's orders, Samson panics after running over one and mistaking it for a firework. Despite Bradford trying to inform Samson what actually happened, Samson panics and runs away, taking his train and Bradford with him. He ends up running over several more detonators, making him panic even more, causing him to nearly hit Rebecca and push Nia and her train down the tracks ahead of him. Samson is eventually diverted onto a siding and hits a set of buffers, where he calms down and is informed what had actually happened. Lost, he eventually sees fireworks high in the sky and follows them to find his way back and ends up at Ulfstead Castle, finding Thomas, Emily, and Rebecca there, who commend him on conquering his fear of fireworks.
- Annie and Clarabel
- Sir Topham Hatt
- Samson's Driver
- Sir Robert Norramby (does not speak)
- James (cameo)
- Percy (cameo)
- Vicarstown Bridge
- Knapford Station Yard
- Ulfstead Castle
- Kirk Ronan Junction
- Blue Mountain Quarry (mentioned)
- This episode is an adaptation of the twenty-second season episode of the same name.