NWR Origins is a mini-series of The Engines of Sodor that portrays the NWR engines' backstories and their arrival to Sodor. The first season began airing on December 3, 2015 and finished on January 24, 2016. These episodes celebrate the 70th anniversary of the RWS and the 100th anniversary of the NWR.
The second season began airing on January 18 and finished on February 1, 2019.
The first nine episodes focus on how engines from the NWR 11 arrived on Sodor or the events surrounding their arrival. Thomas and Edward's episodes take place in 1915, with the opening of the North Western Railway. Henry's episode takes place in 1922, and Gordon's two episodes take place the following 3 years. The previously mentioned 3 episodes also deal with the conflict involving 98462 (Alfred) and 87546. James's episode takes place in 1945, and focuses on events from Thomas and the Breakdown Train and what happened afterward. Donald & Douglas's episode, taking place in 1959, focuses on their plan to smuggle Douglas along with Donald. Oliver's two episodes focuses on Oliver's life on the GWR, the decline of steam, and his escape from scrap.
The second season focuses on the remaining three main characters (Percy, Toby, and Duck) and also explores the origins of Mavis, Bill, Ben, and Boco.
Season 1 (2015 - 2016)
- Tank Engine Mixup (Thomas) - 108 arrives on the island as an engine who was supposed to be in Ireland, but is chosen to stay after learning the other engine (107) ended up in the factory, 108 is given a blue coat of paint is then called Thomas as he is named after a young boy.
- Two's Company (Edward) - Edward arrives on the railway, only for Thomas to be jealous of him because of how he is repainted, resulting the two into quarreling until they get told off by the Fat Controller. Both engines soon work in the end.
- The Trouble with Three (Henry) - Henry arrives along with 98462 and 87546 to help around the North Western Railway after it was being opened. Henry suffers trouble pulling his train due to the fact that he has a small firebox that can't work properly. He feels like nobody loves him after being scolded by the Fat Controller for being late and mocked by 98462 and 87564, then soon realizes he is gentle with the coaches and can get the passengers to the station on time, he believes he can.
- Pride of the LNER (Gordon, Part 1) - Gordon arrives on the island from Doncaster, and is to pull his very own first passenger train, only for him to go 100 miles per hour on the way to the station.
- Disgrace of the LNER (Gordon, Part 2) - Gordon realizes that Alfred never changed and tells Alfred he can't be trusted because of the way he treated Henry along with 87546. After a fight, he avoided him after being scolded by the Fat Controller. As time went on, The Fat Controller realizes he can't keep Alfred on his railway anymore after he felt idiotic of him for keeping him around, only for Alfred to become mentally insane, which leads to the rest of the story being dark and disturbing.
- Splendid Red (James) - James arrives and comes to the railway to pull some trucks. But after his accident, he gets a new coat and his job is to take a slow goods train stopping at every station after the event where Thomas got his very own branch line.
- Smuggling from Scotland (Donald and Douglas) - When steam engines are declared no longer efficient as said when diesels have started taking over, Donald is to be sent to the Sodor railway as said by a really mean Scottish controller, but Donald gets the plan of bringing his brother with him in an idea where neither would be separated.
- Great Western End (Oliver, Part 1) - When the diesels started taking over for steam engines in the Great Western Railway, Oliver makes a plan journey to be escaped from certain doom after William was bought for another railway.
- Great Western Escape (Oliver, Part 2) - Oliver still makes his escape journey with Toad and Isabelle, but ends up at the scrapyard at Barrow in Furness. He loses all hope until Toad tells him something that is with him to the very end. He is later escaped from scrap after Douglas saved him from being incinerated (which is a word for "scrapped").
Season 2 (2019)
- Little Green Menace (Percy) - 6 arrives on the Great Western Railway and wreaks havoc by heckling the other engines until the manager sent him to the workshop. He met an engine there called The Flying Thistle, who gave him advice about having a laugh with others while working hard. 6 would eventually be bought by the Fat Controller for the Island of Sodor and named "Percy".
- Country Tram (Toby) - Toby arrives on his old line at Arlesdale End, where he met his coach Henrietta. As time went on, he starts to gain more experience with trucks.
- The Way of the GWR (Duck) - Montague arrives on the Great Western Railway where the big engines order him about and start calling him "Duck". He was then given advice on how to stand up to three big engines, which earned him his no-nonsense personality.
- Troublesome Twins (Bill and Ben) - Two twin engines called Bill and Ben were bought to work at the China Clay Quarry and caused mischief for Edward and the workmen. Their prank backfired, however, when a train of China Clay cars rolled towards them.
- Feisty Girl (Mavis) - A feisty, young diesel named Mavis came to work at the Ffarquhar Quarry, who started to re-arrange the trucks in different places, to Toby's dismay. After stopping at the level crossing, Mavis was scolded for jauntering down Toby's line, but redeemed herself after she rescued Toby from a tightrope.
- Writings on the Wall (Boco, Part 1) - When BoCo starts his first day operating on the Mainland, his engine starts overheating, and was taken to the works. To his horror, the manager migrated him and the other Class 28s to Barrow-in-Furness, to their dismay. Just as D5703 starts up on his passenger train, his engine overheated and caught fire. BoCo was saddened and angered when being informed that his brother was scrapped afterwards.
- A True Diesel (Boco, Part 2) - BoCo greets Vulcan, only to have ties cut off with him, leaving him with no friends left. He volunteers to take a goods train from Barrow to Brendam, where he encounters a broken-down Edward. With Vicker's words, he offers to help Edward get to Brendam station. After getting stuck on a hill, Douglas took BoCo to the works where Edward introduces Henry to him. When the other sympathize with his faults, the Fat Controller has decided to purchase BoCo to help out on the Brendam branch.
- Donald and Douglas
- Sir Topham Hatt I
- Sir Topham Hatt II
- The Scottish Controller (not named)
- Oliver's Siblings (Clarence and Paul speak)
- Flying Scotsman (does not speak)
- Pip and Emma (do not speak)
- Toby (cameo)
- Emily (cameo)
- Stepney (cameo)
- Spencer (cameo)
- Rosie (cameo)
- 106 and 109 (cameo)
- Mavis (cameo)
- Salty (cameo)
- Boco (cameo)
- Daisy (cameo)
- Bear (cameo)
- Diesel 10 (not named, does not speak)
- Annie and Clarabel (cameo)
- Spiteful Brake Van (cameo)
- Wretch (unintentional cameo)
- Thomas: JakerBraker123
- Edward: EnterprisingEngine93
- James: Andrew Homer
- Donald and Douglas: Carson0802200
- Oliver: The Peel Godred Branch
- Toad: Donald9andDouglas10
- 98462, Bill and Ben: DarthWill3
- Eagle: Kanefan701
- No. 107, Reporter, Jinty, William and Flying Thistle: 22Tesla
- Percy: Christopher Bouchard
- Toby: Matts
- Henrietta: DarkMagicalYoshi
- Duck: Waltsland1912
- Mavis: Mika Michelina
- Boco: Victor Tanzig
- Everyone Else: Thomas1Edward2Henry3
- This is not an actual remake of The Adventure Begins. In T1E2H3's universe as well as the Railway Series, the engines arrived in order of their numbers, with Thomas being the first in 1915.
- A teaser trailer was released on September 25, and a full trailer with footage from the first two episodes was released on October 21. A second trailer, with actual dialogue, was released on November 12. The final trailer was released on November 30, and used music from the trailer for the movie Star Wars Episode VII: The Force Awakens.
- T1E2H3's timeline of Sodor events differs from the general fan accepted timeline. The events of the Three Railway Engines takes place in 1924, while every subsequent book takes place the year before the publish date. (ex. Thomas the Tank Engine takes place in 1945).
- Originally, there were no episodes intended to be dedicated to Percy, as well as Toby and Duck as it was already shown in the RWS and TV series how they arrived and T1E2H3 stated that their episodes would just be remakes of the TV episodes, which would be uninteresting. He had originally planned to leave James out for the same reason.
- However, episodes of their origins appeared in Season 2.
- Originally, there was going to be an episode dedicated to Diesel which would show what happened whilst Duck was at Wellsworth. However, it was cut because it would add another long story that would require work. The idea was then used in The Devious Diesel and Sent Packing.
- This is the first time voice actors are used since The Search for Smudger.
- Filming began on September 6, 2015.
- The engines were portrayed in the following liveries: Thomas in his LB&SCR maroon, Edward in his Furness Railway maroon, Gordon in his LNER Green, James in his L&YR black, and Oliver in his BR dark green.