Boomer's Reign

Plot
Patrick Boomer has once again gotten three of his diesels on trial on the North Western Railway and has decided that now is the time to execute his plan of revenge. He sends Diesel 10, Splatter, and Dodge to the North Western Railway to infiltrate its interior and orders them to remain there until he is able hijack Henry in the impound. The three engines arrive on the railway and are greeted somewhat warmly by the others, but are given the cold shoulder after they leave for a job. Duck especially express his concerns and suspicions while Edward tries to convince everyone that these diesels could be different. Gordon then makes a petty jab at Donald who is still upset over Douglas' arrest. The next night, Donald states that once Douglas returns to his old railway, Donald would be joining him. However, Charles Hatt arrives to inform the engines that Douglas would be staying on the railway. The engines cheer and Donald is relieved.

A few nights later, Diesel 10 claims that he has a night job and that he needs the assistance of Splatter and Dodge. The three diesels leave and Donald decides to follow them out of curiosity and suspicion. He arrives at the station and sees them talking to Peter Boomer. He is then spotted and dragged away by Diesel 10.

At the Barrow-In-Furness impound, Henry is all on his own. Henry is informed that both Donald and Douglas will be staying on the railway and that both will be there when he gets back. However, Patrick Boomer emerges and reintroduces himself to Henry. After much resistance, Boomer manages to get Henry out of the impound while killing 3 officers and wounding two others by gunshot in the process.

Meanwhile, Thomas, Edward, and Gordon decide to check on Donald and leave Percy, Toby, and Duck behind at the sheds. They arrive at Knapford Station where Edward and Thomas are immediately infiltrated by Splatter and Dodge. Diesel 10 attempts to catch Gordon but Gordon manages to escape when Diesel 10 is diverted onto the Wellsworth Branchline after a lengthy chase. Gordon arrives at Crovan's Gate where Sir Bertram Topham Hatt is with his son, Charles. Meanwhile, Boomer returns to his workshop with Henry and activates the bombs at Knapford Station and Knapford Sheds. 46 people die at Knapford and Toby gets caught in the explosion in the explosion. Diesel 10 manages to catch up to Gordon and the Fat Controller at Crovan's Gate and chases them all the way to the mainland. The Fat Controller manages to get Gordon to juke Diesel 10 and they return to Sodor. They return to Crovan's Gate sheds where the little engines and Mr. Hugh assist in hiding the Fat Controller from Diesel 10. Diesel 10 manages to derail and heavily damage Skarloey's boiler before Sir Handel takes off with Bertram and Charles in his cab. Diesel 10 pursues them, but realizes that Peter Boomer has gone after them in Rusty.

After James is captured by Splatter and Douglas manages to escape being kidnapped by Dodge, Boomer informs Henry that his plan involves killing the Fat Controller and destroying as much of the railway as possible. Henry protests by saying that Boomer will fail and the engines will rise victorious, but Boomer retaliates by stating he'll kill Henry as well. Elsewhere, Sir Handel has arrvied at the top station and the Fat Controller inform the authorities and his brother Lowham of what is happening. Rusty then arrives carrying Peter. Both are stopped by Duncan who biffs Rusty, derailing him and knocking out Peter. They then return to Crovan's Gate.

At the works, Splatter shoves James into the siding alongside Thomas, Edward, and Donald. Diesel keeps guard until Edward convinces him that what he is doing is wrong. Diesel leaves the works leaving the engines unattended. Duck and Percy are attempting to rescue Toby with Rocky when Splatter arrives and attacks Duck.

Douglas manages to escape to the Barrow-In-Furness scrapyards where he comes across Oliver. After remembering his brothers' words, Douglas decides to rescue Oliver when they are spotted by Dodge. Diesel meanwhile rescues Annie and Clarabel at Knapford Station and takes them to the Barrow-In-Furness police station and informs the police that he knows where Henry is. The police go with Diesel to rescue Henry. Dodge chases Douglas and Oliver all the way back to Knapford when they are diverted onto different lines. Douglas and Oliver are diverted onto the sidings, but Dodge is accidentally diverted onto Duck and Splatter's line and biffs them, causing all three of them to ram into the burning shed.

Meanwhile, the Fat Controller, Charles, Mr. Hugh, and Sir Handel return to Crovan's Gate where Lowham informs them that Knapford Station and Knapford Sheds have been bombed. He also informs them that Percy and Toby were taken by Diesel 10. The Fat Controller realizes that Gordon, Duck, James, and Douglas are all that's left. Gordon soon returns from hiding and James is rescued from the works by Mr. Hugh. Gordon goes to find Diesel 10 and James goes to find Boomer. They arrive at the workshop and Bertram, Lowham, and Bertram's bodyguards go inside leaving Charles, Mr. Hugh, and James outside. They get inside but are all immediately shot by Boomer. Charles rushes inside and shoot Boomer, but Bertram is quickly shot by Boomer again after supposedly surviving. Boomer is then shot by Mr. Hugh, marking the near end of the attack. The police show up shortly after.

Back at Knapford, Thomas, Edward, Gordon, and Percy return to rescue the coaches when Douglas arrives with Oliver to inform them that Duck is buried underneath the shed. Diesel 10 suddenly races past attempting to escape. Percy stays to help Douglas while Thomas, Edward, Gordon, and Oliver go after Diesel 10. Donald soon joins them but Edward breaks down shortly after and gets knocked out, leaving him severely damaged. The rest of the engines go after Diesel 10 and manage to stop him thank to the help of Henry, James, and Diesel.

The engines return to Sodor where Charles states the effects of the attack. He declares himself successor and director of the North Western Railway and purchases Douglas and Oliver as members of the Railway. The episode ends with Adam Norman being revealed to be the son of Peter Boomer, and Peter escaping the island via airplane.

Characters

 * Sir Bertram Topham Hatt
 * Patrick Boomer
 * Henry
 * Diesel
 * Gordon
 * Edward
 * Charles Topham Hatt
 * Diesel 10
 * Thomas
 * Duck
 * Donald
 * George Hugh
 * James
 * Toby
 * Percy
 * Douglas
 * Lowham Hatt
 * Peter Boomer
 * Sir Handel
 * Skarloey
 * Rusty
 * Duncan
 * Splatter
 * Dodge
 * Oliver
 * Adam Norman
 * Linda Norman
 * Verity Norman
 * Henrietta
 * Bodyguard 1
 * Bodyguard 2
 * Peter Sam
 * Annie
 * Clarabel
 * Toad
 * Stephen Topham Hatt

Deaths

 * 46 people at Knapford Station bombings
 * 3 Police Officers
 * Bodyguard 1
 * Bodyguard 2
 * Sir Bertram Topham Hatt
 * Patrick Boomer
 * Duck's Driver
 * Duck's Fireman
 * Splatter's Driver
 * Dodge's Driver
 * Duck
 * Toby
 * Edward
 * Skarloey
 * Splatter
 * Dodge

Trivia

 * GTSH considers this episode to be his best episode to date by a long shot.
 * Despite the hour length, this episode only took 2-3 months to produce, shorter than almost half of the other episodes so far.
 * This episode utilized a total of 35 sets, including over 10 countryside sets and around 10 stations.
 * This episode utilizes the most characters of any episode to date.
 * Boomer and Bertram were supposed to have a longer confrontation scene, but that was scrapped.
 * Donald was supposed to have a fight scene with Splatter and Dodge.
 * Thomas and Edward were also going to fight Splatter and Dodge initially.
 * Diesel was originally going to die in this episode.
 * Gordon's role in this episode was greatly increased in the final draft.
 * Oliver and Toad were added into the second draft of the script.
 * This episode holds the record for most drafts written or partially written with 7.
 * Diesel was also going to have a fight scene with Splatter and Dodge at Tidmouth Sheds.
 * There was a scene with the engines at Tidmouth Sheds after Charles' speech at the end of the episode, but that was cut.
 * Peter was decided to be Adam's father during the 3rd or 4th draft.
 * The scene with Adam Norman being revealed to be Boomer's son wasn't supposed to happen in this episode, but GTSH felt it was a better way to introduce Adam's story.
 * Donald was initially going to get extremely injured during this episode, but that idea was scrapped in the final draft.
 * Peter was initially going to kill his father, but that was changed to Mr. Hugh.
 * The argument scene with Boomer and Henry was added during production of the episode.
 * Proteus was meant to make an appearance, but GTSH neglected to include him.
 * Peter Sam, Annie, Clarabel, Toad, and the bodyguards do not have a single line of dialogue in this episode.
 * Patrick was initially going to kidnap Bertram and Charles and force them to watch Knapford's destruction, but the scene felt way too similar to the finale of Sudrian Conflict and Bertram's role was changed significantly.
 * Diesel 10 was intended to be seen with scars on his face after his big crash, but the shots were cut.
 * The piece 'Padme's Destiny' from Revenge of the Sith was supposed to play during the Adam Norman scene, but was replaced with 'Your Father Would be Proud' from Rogue One.
 * Arry was initially going to appear and help Douglas and Oliver escape, but his appearance was reduced to a cameo alongside Bert in Episode 9.
 * Patrick Boomer, Bertram, Sir Handel, Gordon, and Henry were all intially going to swear in the finale.