On their way to a celebration for Thomas' 10,000th delivery, Percy tries to help Thomas with his big speech.
Bruno helps Diesel with a heavy load to the lighthouse; Bruno tries suggesting a safer route, but Diesel doesn't wait long enough to listen to him.
While Kana and Thomas deliver aquarium materials for the Vicarstown Fish Day, it's up to steady Percy and Nia to deliver the fish themselves.
When Ashima is set to arrive on Sodor, Thomas and friends attempt to go the extra mile in order to make the island seem fantastic!
The engines rev up for their homemade obstacle course event known as the Tri-and-a-half-a-lon; during practice, Nia worries that she's never been able to beat the timer, but Sandy and Carly encourage her to keep practicing before the event.
When Carly gets a new magnet to help Tess the Troublesome Crane load up a shipment of metal crates, she struggles with the new tool; Carly is frustrated that she's making mistakes during the job, but Sandy and Thomas reassure her.
After Percy gets in an accident, Nia temporarily takes over his mail delivery duties for him, and her mail delivery is even quicker; Percy thinks the replacement is permanent, so in an attempt to find his new thing, Percy tries out different jobs.
Thomas and Percy are excited to deliver a special balloon for the hot-air balloon festival, but the balloon is wrapped up tight; they're told not to peek at it until they arrive; while making the delivery, part of the balloon pops out of its tarp.
Carly has developed a terrible squeak, and Sandy finds an oil can to give her as a feel-good surprise; Sandy is motivated to keep making the fix bigger and bigger until she's created a wacky robot oil can squirter.
A storm knocks out power for the whole island, and Thomas volunteers to deliver a generator from Kellsthorpe to Knapford.
Thomas and Percy explore a brand-new track the evening before the route is opened everything seems new and exciting, and even a night spent stuck in the mud turns into a wonderful experience.
Thomas and the other young engines encounter a stink monster that threatens to spread a stench all over Knapford; when the monster kidnaps Percy, the rest of the Biggest Adventure Club band together to save their friend.
With the holidays just around the corner, Thomas and Percy are determined to deliver the mail to all the patrons of Sodor.
It's Christmas time in Sodor and every engine is excitedly preparing for the holiday, especially Bruno who is excited to put his star on the tree.
While out on a delivery to Whiff's Recycling Plant with Boxy in tow, Thomas realizes that his pal is on his last crooked axle.
After a storm causes a rockslide in Crumble Canyon, mountain engine Ashima is eager to clean and clear the chaos with her new friends, but Thomas is concerned the mess could ruin her paint.
Thomas is thrilled -- Sir Topham Hatt has given him a snowplow in preparation for a big storm on the way, and the Number One Engine is ready to show off his skills!
When Gordon is given an all-day responsibility on the far side of Sodor, he recruits Thomas to be the temporary Engine in Charge.
Tired and in need of relaxation, Kana decides to take a well-deserved break between deliveries.
Abuzz with excitement about the Sodor Flower Festival, Thomas is given the important task of transporting Sir Topham Hatt's prized roses to the event.
Nia must get a huge Earth ball from Whiff's Recycling Plant to Norramby Beach, but all the rail lines are blocked.
When Diesel discovers that he doesn't just like to be known for his incredible strength; he finds an unlikely compatriot in Kenji, who is tired of only being known for his swift speed.
It's Valentine's Day and no one on Sodor is happier than Percy; he gets to deliver everyone's gifts to their friends throughout the island.
As the other engines prepare for a Valentine's Day party, Kana is worried: she doesn't know what to bring!
On Plant-A-Tree Day on Sodor, Thomas and Diesel both want to deliver the most impressive pine for the holiday, but they'll have to compete by delivering all the other trees first.
Cranky gets overwhelmed on a busy day at Brendam Docks and gets Riff and Jiff's names confused and sends them on silly deliveries; even though Thomas hears the mistakes, he doesn't correct the crane, a decision that creates chaos in Sodor.
While passing through the pastures of Sodor, Thomas, Percy and Diesel find a sheep all by herself; when the sheep takes a liking to Diesel, the three engines decide to let her sleep with them in the sheds until they can find out where she came from.
When a new express tunnel opens in Sodor, both Thomas and Diesel want to be the first one through; but their stubbornness may prevent them from enjoying the spring butterfly migration.
When Carly does not return from saving Emily from an accidental derailing, a worried Sandy recruits the help of a bored Diesel to find her best gal pal; the unlikely pair become detectives, traveling throughout the island in search of clues.
When he accidentally causes all the lamp posts in Vicarstown to fall and shatter, an embarrassed Sir Topham Hatt requests Thomas to go on a secret mission to Harwick for replacements in time for the evening concert.
After another victorious race, Kana seems unbeatable; no engine on the island is as fast as Kana; this does not stop Sandy from challenging the electric engine.
When a precious marble statue of his great-grandfather arrives, Sir Topham Hatt enlists the help of Thomas and Bruno in delivering it to Vicarstown Plaza.
After Salty the Diesel Engine returns from his worldly travels, he sings a shanty to Thomas and Percy about a legendary treasure lost on the island of Sodor; the two friends are eager to see if the legend is true.
On a particularly blustery Balloon Festival day, Thomas is tasked with retrieving any balloons that start to drift away; when the Kraken-shaped balloon soars off, the chase is on.
Thomas learns that the rocket he helped deliver is finally falling back to Earth into the ocean outside Sodor; Bulstrode, Carly and their team of retrieval experts are on the job to fish the rocket out of the water.
After Sir Topham Hatt messes up his instructions for Kenji's passenger delivery, Thomas is asked to set things right; as Thomas follows Kenji's trail, he forgets to ask his friends for specific directions, which prevents him from catching up.
Thomas gets help from Terence and Carly to assemble hay bales; Terence purposefully crashes into the hay bales; they turn the hay-bale stacking into a game, forming all kinds of structures Terence can crash into.
When the engines have the day off to play, Percy is asked to referee their obstacle course race.
When Thomas and Percy transport an unlucky boxcar of bananas, Thomas starts to have bad luck wherever he goes and must find a way to break the curse.
When Nia causes an accident that sends sand into Tess's gears during a big delivery, Nia tries Sandy's new super-grease as a solution.
The engines are excited to see the Northern Lights with Harold the Helicopter.
Bruno's beloved map gets carried away by the wind.
When Percy and Kana have a near-collision, they enlist Safety Engine Emily and go to ridiculous extremes to introduce safety measures all over Sodor.
When Bulstrode and Cranky get into their crankiest fight yet, they learn how to express their feelings in order to save their friendship.
Thomas plays a new game called "Switcheroo", but gets lost and learns the value of routines.
When Percy is accidentally doused in blue paint, he gets the opportunity to be Thomas for a day.
When aging Toby comes to Knapford, he struggles to keep up with all the young engines; he still has a lot of zip in him, but around all the modern engines, he loses his confidence.
When an important shipment is delayed, Bruno and the gang have to learn the great value of waiting patiently.
When Thomas and Diesel both want to deliver the same load to Whiff's Recycling Plant, Thomas suggests they each take half of the load, but Diesel turns it into a race.
It's rocket launch day and all the trains get to help deliver the big rocket parts, but when Thomas is assigned a tiny part, he puts it off to help the others with their more exciting parts.
When Percy has to deliver a new light bulb to the lighthouse at night, Thomas suggests playing secret agents along the way to help Percy forget about his fear of the dark.
When Thomas builds an obstacle course for his friends, he gets upset when they won't play with it his way.
Thomas volunteers to get Annie and Clarabel across Sodor without waking them up, only to discover that it's going to be harder than he imagined.
When Kana's power goes out during a delivery run, Thomas teaches her that sometimes it's okay to go slow.
Thomas has the honor of pulling the dragon to the Medieval Faire, but everyone wants a turn as well.
When Thomas finds a treasure map, he creates The Big Adventure Club to seek the treasure; Sandy wants to join but Thomas says she's too little, so Sandy forms her own club.
When Thomas borrows Percy's lucky bell for a dangerous delivery, Thomas accidentally loses the bell.
When Sandy learns about a massive shipment of sand that needs to be delivered, she is determined to help despite her size.
When the trains must deliver in pairs, Thomas is disappointed to be paired with Diesel instead of his BFF Percy.
Thomas and Percy volunteer to deliver a herd of cows, but the cows keep wandering off on their own adventures.
When music-lover Nia gets stranded before a big concert she's been waiting to see, Thomas brings the concert to her.
Thomas misunderstands the Backwards Day game and accidentally delivers the wrong cargo to the wrong places.
Thomas and Kana journey across Sodor to find the prize at the end of a rainbow.
Nia transporting a giant balloon to a parade at Vicarstown, but the strong wind and other hazards along her route attempt to ruin her plans.
Percy loses Nia's parade flag just before the big parade; Thomas assists in looking for it before the event starts.
Kana is upset when she keeps running out of power, but a mystery scavenger hunt is just the thing to cheer her up.
Thomas pretends to be a hero to help ensure the movie screen Nia's delivering arrives clean and pristine.
Thomas, Percy and Nia have to make a delivery to Wayland on the Mainland; the trip will take a couple of days; they have to camp out in the woods overnight, but Percy is anxious.
When Thomas and Percy's plan to surprise Diesel goes awry, the two friends still manage to cheer up Diesel, just not in the way they expected.
When Thomas helps Nia make a delivery to the beach in Norramby, he insists he knows a shortcut and leads the way; it turns out his memory isn't as good as he remembered.
When all the trains but Thomas get deliveries, he's left to spend the day alone; with the help of an old boxcar and a battered beachball, an adventure unfolds.
When Thomas' #1 gets covered by paint, Diesel's comment about Thomas not being number one anymore causes him to doubt himself.
The engines look forward to the roller coaster at the Vicarstown Carnival, except for Percy, who's a bit afraid.
Thomas is so excited to show Annie and Clarabel's passengers the scenic views of Sodor, but then the power goes out all over the island.
When Yong Bao visits Sodor, a jealous Thomas sets out to prove he's the braver train and challenges Yong Bao to a series of bravery challenges, only to have his plan backfire.
Thomas and Percy think they're great communicators but when they're tasked with delivering a submarine to Vicarstown, communication becomes a bit more difficult.
Thomas and Percy have a difficult delivery: getting eggs and other cake ingredients safely to Vicarstown for their bake-off.
When the engines are delivering attractions to the annual Harwick Beach Carnival, a series of mistakes causes the precious Calliope to break; luckily, the engines come up with a creative solution.
Thomas and the other engines are enlisted to deliver some newly discovered dinosaur bones, but they must deliver them in the correct order for assembly, which isn't as easy as it sounds.
Gordon is unable to make an important delivery on his own; when Thomas offers his help, Gordon insists on second-guessing Thomas' every move.
When Thomas accidentally breaks a light he's hauling to the Sodor Festival of Lights, he learns the best way to be the No. 1 engine is to be honest after making a mistake.
Nia shows Thomas and Diesel how much unique beauty exists in Sodor, which comes in handy when they need plants to beautify a plaza in Vicarstown.
When Thomas' whistle suddenly stops working, he learns that he doesn't need his whistle to still be himself.
Thomas and Percy get into their first big fight and are afraid that their friendship is over, until Nia helps them figure out how to resolve it.
Nia has volunteered for a big day of deliveries and is determined to make the perfect plan to get it done, but when things start to go awry, she doggedly sticks to her plan and refuses any help.
On the last day of Yong Bao's visit to Sodor, his friends dig up a giant keepsake to help him remember them.
When a big storm approaches, Thomas and company must complete a week's worth of deliveries by the end-of-the-workday whistle, but Sandy needs repairs.
While the trains are setting up for the Vicarstown Fall Festival, Thomas is feeling down about the end of summer and the changing weather.
When Thomas throws away Diesel's favorite oil can thinking it's trash, he makes a promise to get it back and learns it's better not to touch things that aren't yours.
While playing hide and seek with Percy, Diesel accidentally gets stranded on a barge that floats out to sea.
Thomas and Diesel take a friendly competition too far and put an important delivery rescue at risk as they race across Sodor.
Thomas is elated when he finds a cowbell on the side of the tracks, until his friends start hogging it.
When Sir Topham Hatt's Hat blows away in the wind before making an important announcement, Thomas and his friends race around Sodor, trying to catch it; the hat remains out of reach until they learn to work together.
Thomas spends the day alone; Thomas gets covered in paint.
Thomas and Diesel take a friendly competition too far and put an important delivery rescue at risk as they race across Sodor; Percy announces he's giving up his ghost-scaring machine because the machine is good for more than just scaring ghosts.