A Thomas Promise

"Don't worry, Gordon... ugh... I'll get it there for you! I Thomas Promise!"

- Thomas making a promise

A Thomas Promise, also known as Thomas' Promise, is the first episode of the first series and the first episode of Thomas & Friends: All Engines Go altogether.

Plot
Thomas is out playing a stacking game with Carly and Sandy, with Percy as a spectator. After beating his record and recovering his nearly fallen stack, Thomas gets his flatbed stolen by a newly arrived Diesel, who intends on beating Thomas and succeeds with help from Carly and Sandy. Severely annoyed by this, Thomas attempts to take back his flatbed, but neither he nor Diesel intend on letting go, and their couplings end up snapping. The force sending its load of sleepers flying into the air. They then fall as a cage around Percy, a house around Diesel, and a pile on Gordon's line, the latter of which forces him to jump, though the sleepers get caught between his tender and cars and breaks his rear coupling. Sandy then inspects the cars, and Gordon reveals that before his coupling was broken, he was delivering a load of recyclables to Whiff's Recycling Plant. Feeling bad for the incident, Thomas promises to finish the delivery for Gordon, but the train is too heavy for him to pull alone. He ends up sharing half of the train with Diesel so that the two can have a race, and wanting to see who wins, Sandy follows after them, with Carly and Percy close behind.

As the two make their way to the Recycling Plant, Thomas manages to beat Diesel to the Tunnel of Zoom. Sandy, Carly and Percy hear his whistle from the tunnel, and as Thomas exits, Diesel manages to overtake him, blinding the blue engine with smoke before switching the tracks to send him off course. As Carly, Percy and Sandy look for Thomas, they see him in trouble; Diesel's switching had left him on a collision course with Kana. Forced to jump over her to avoid a crash, he ends up losing some items that fly over Sandy, Percy and Carly. Diesel chuckles about his advantage, but catching up behind him, Sandy tosses a traffic cone and hits a switch, sending Diesel down a different route. Thomas is then reloaded with his runaway items as he switches back onto the right track, only for Diesel to switch himself onto the track next to him and race the tank engine towards the steep hill. Thomas proves to be carrying a lighter load, but Diesel, determined to win, transfers a heavy refrigerator from his train into Thomas', weighing down the tank engine and causing his cars to break away. Although Percy manages to avoid both the cars and Thomas, Carly accidentally switches them onto a track heading towards a mud pit, leading to both falling in and Thomas feeling dejected. As Carly winches him out, she, Percy and Sandy give him words of encouragement, and Thomas is back on his mission.

Thomas continues his way back up the hill, and determined to help him keep his ‘Thomas Promise’, Percy, Sandy and Carly all bank him up the slope. Making it to the top, Thomas spies Diesel waiting impatiently for a boat to pass through the open Quickdraw Bridge. Unfortunately, in his haste to win, Diesel is oblivious to his train losing it's contents. Seeing this, Thomas ultimately decides to stop and keep his promise to deliver all of Gordon's cargo. With the help of Percy, Carly and Sandy, Thomas picks up all of what Diesel leaves behind. Diesel ultimately beats the others to the Recycling Plant, but upon seeing Thomas's large load, is shocked to see his cars empty. The others eventually explain what happened, and as Gordon thanks Thomas, the little blue engine gives his gratitude to his friends, including a very surprised Diesel. Sandy later repairs Gordon's coupling, and as he sets off Thomas and Diesel begin another race, with Sandy, Percy and Carly not too far behind to watch.

Characters

 * Thomas
 * Gordon
 * Percy
 * Diesel
 * Kana
 * Carly
 * Sandy
 * Whiff

Locations

 * Tidmouth Sheds
 * The Tunnel of Zoom
 * Quickdraw Bridge
 * The Funnel Tunnel
 * The Broken Bridge
 * Whiff's Recycling Plant
 * The Maintenance Yard

UK

 * Aaron Barashi as Thomas
 * Will Harrison-Wallace as Gordon
 * Henri Charles as Percy
 * Henry Harrison as Diesel
 * Eva Mohamed as Carly
 * Holly Dixon as Sandy
 * Chloe Raphael as Kana

US

 * Meesha Contreras as Thomas
 * Neil Crone as Gordon
 * Charlie Zeltzer as Percy
 * Shomoy James Mitchell as Diesel
 * Jenna Warren as Carly
 * Glee Dango as Sandy
 * Ava Ro as Kana

Song

 * I'm Gonna Chug

Trivia

 * This episode marks the first of a few things:
 * The first episode of All Engines Go.
 * The first episode using Flash animation instead of three-dimensional animation.
 * The first and only episode to date to be written by Rick Suvalle until the 2023 special Special.
 * The first production since the original series episode Whiff's Wish to have a completely different voice cast in the US and UK dubs.
 * Rick Suvalle finished writing this episode around December 2019 and started writing in October 2019.
 * According to Rick Suvalle, Whiff was originally going to appear in this episode. However, he was ultimately dropped due to budget constraints, this should have been Whiff’s only appearance in the first series.
 * In the Latin American Spanish dub, this episode is called "A Promise From Thomas".
 * On US, Canadian, UK and Irish TV guides, this episode is titled Thomas' Promise. As seen in the auditions script from January 2020 (which replaces the name "Thomas" with "Riley"), this appears to have been the original title.
 * Thomas would use his "Thomas Promise" catchphrase in later episodes.
 * In a leaked early trailer from January 2021:
 * Diesel has an alternate expression in the scene when he first appears.
 * Gordon chases Thomas down when he falls into the mud pit instead of Carly.
 * In an early version of the script from January 2020 used for auditions:
 * Several characters' names are changed in order to keep the series a secret.
 * Thomas is named Riley.
 * Percy is named Tom-Tom.
 * Diesel is named Joey.
 * Carly is named Eva.
 * Sandy and Kana have their original names, Dusty and Akira respectively.
 * The beginning of the episode takes place at the Maintenance Yard rather than in front of Tidmouth Sheds.
 * Kana (Akira) appears at the start of the episode racing Diesel (Joey) when he enters the yard.
 * Thomas (Riley), Percy (Tom-Tom), Carly (Eva) and Kana (Akira) are revealed to all be eight years old, while Sandy (Dusty) is six.

Goofs

 * In the beginning of the episode, the flatbed Thomas uses has blue wheels. But when Diesel tells Carly to load him up, the wheels are now black as is some of the trim. A few scenes later, the flatbed has blue wheels again.
 * When Gordon says he is happy, the top of his funnel is missing.
 * Sandy inexplicably gains buffers while pushing Thomas up the hill, but they vanish afterwards.
 * When Gordon jumps over the sleepers, his back wheel disconnects from his axle.
 * When Thomas says "Huh?", his wheels are moving backwards.
 * Ava Ro is not credited for voicing Kana in the credits for the US dub.
 * During the song, I'm Gonna Chug, Diesel says "I'm gonna chug, I'm gonna choo", despite him being a diesel engine.
 * When Diesel sets off, Gordon can still be seen with three hoppers despite all six being coupled to Thomas and Diesel. This error lasts until Carly, Sandy and Percy roll off-screen.
 * During the first portion of the song I'm Gonna Chug, Thomas and Diesel are consistently changing tracks.
 * Percy's lamp is on the wrong side of his running board when he catches the tire.
 * When Diesel says "I won! I won the race!", his buffers and coupler detach from his bufferbeam and fall under his footplate.
 * When Thomas, Percy, Carly and Sandy arrive at the recycling plant, Percy has no buffers and Carly's headlights appear to be elongated.
 * In the Milkshake! and Nick Jr. airings, the US dub credits appear at the end as opposed to the UK dub.
 * In the UK dub, when Percy says "Quack", he has his US voice.
 * When Diesel enters the recycling plant, the third hopper car is missing details.
 * In one shot of Gordon at the Recycling Plant, his funnel is moved too far down.

Merchandise

 * Push Along
 * Motorized

US/CAN

 * Time for Teamwork!