Thomas Makes a Mistake is the eighth episode of the twenty-third series.
When Thomas arrives at the Varkala Railway Station, Charubala gives Thomas a very important job of delivering some very important silk to a famous fashion designer in Surajpur. She tells Thomas to take a turning after the lake and the next station after that is Surajpur. Thomas sets out to deliver the silk and sees a lot of new and exciting things on the railway; a mountain railway, Camels and even swimming Elephants. Unfortunately, he gets distracted by the Elephants and accidently goes the wrong way.
Thomas delivers the silks to a station where Noor Jehan is. When she realises what he's delivered, she attempts to call out to him but fails. While telling Ashima of his journey to the station, she asks him about things in the station that Thomas didn't see. This makes Thomas realise that he actually took a wrong turning. Ashima attempts to advise Thomas to tell Charubala about what he did, but Thomas thinks she'll be cross with him if he does.
Thomas rushes to collect the trucks he accidently left at the wrong station to drop off at the right one, but Noor Jehan attempts (and fails) to call out to him again. Thomas goes the right way and drops off what he thinks are his trucks, only for several Goats to come out of a truck. Thomas' actual trucks are left at another station and are opened up, only for the silks to fly out of a truck. One of the silks blinds Thomas, causing him to bump into Shankar's trucks of fruit which fall onto the tracks and are very narrowly almost run over by Noor Jehan.
Thomas realises that he needs to confess to Charubala what he did, to which she offers to help him. The Goats, silks and fruits are soon successfully retrieved by everyone, to which Charubala praises everyone for their efforts and Thomas thanks everyone for helping him.
- Noor Jehan
- The Grumpy Indian Stationmaster
- The Friendly Indian Stationmaster
- The Indian Fashion Designer
- The White Tank Engine (cameo)
- The Maroon Tank Engine (cameo)
- The Grey Tender Engine (cameo)
- The Brown Tender Engine (cameo)
- Joseph May as Thomas
- Tina Desai as Ashima and the Fashion Designer
- Nikhil Pamar as the Grumpy and Friendly Stationmasters
- Sheena Bhattessa as Noor Jehan and Charubala
- Sanjeev Bhaskar as Shankar