After an argument during a game results in Gordon breaking his coupler, Thomas and Diesel make it up to him by delivering his train to the Recycling Center. However, Thomas and Diesel are determined to beat each other to the center, causing problems for all involved.

To help Percy conquer his nyctophobia on a nighttime run to the lighthouse, Thomas has the two of them pretend to be secret agents, and Percy learns that nothing is scary in the dark when knowing what is there.

Thomas has to haul Annie and Clarabel to the docks in time for a nighttime passenger run. However, they must be well rested for the trip, but Thomas quickly learns that a noisy day makes it very difficult not to wake sleeping coaches.

Thomas is given the job of delivering a fake dragon to the castle for a medieval festival. However, he refuses to share the job with his friends, and learns that the best experiences are the ones where everyone participates.

Thomas takes Percy's lucky bell on a run to the mines, but despite promising to be careful with it he ends up dropping it down a mineshaft. As they set off to retrieve it with Carly and Sandy, Thomas learns to be more responsible with his promises, while Percy learns to trust others much more than what he believes.

On a job of delivering houses, Thomas is disappointed to be partnered with Diesel instead of his best friend, Percy. Jealous of the fun Percy is having with Nia, Thomas neglects Diesel throughout the journey, and learns that when it comes to having fun with others, best friends are not the only people to hang out with.

Gordon is late delivering instruments for a concert and the engines quickly get him on his way, but when Nia gets stranded on the other side of a drawbridge stuck open, they cheer her up by performing their own makeshift concert using what they learned: any sound can be music.

The engines race towards what they perceive as the end of the rainbow to find the supposed treasure, but it always changes location whenever they get close. Once they actually reach it, Thomas and the others realize that sometimes, the real treasure can only be realized when the bigger picture is seen in full.

Not wanting to be late for a parade, Thomas encourages Percy to rush through his checklist, but learns that it is better to take time and go through every step when they lose Nia's flag for the parade.

For a movie night at Vicarstown, Nia has to deliver the screen that will show the film. However, it must be clean, and even while pretending to be a superhero, Thomas is dejected that they failed to keep it spotless, but learns that there is more than one way to be a hero.

Thomas starts a joking spree on a day that Diesel is determined not to run late on. However, Diesel accidentally takes a boxcar rigged to explode with confetti, and Thomas and Percy have to switch it with his real car before it is too late. In the end, Thomas learns that someone has to be in the mood to laugh, while Diesel learns that laughter can brighten up a very bad day.

When Thomas learns that he does not have any jobs assigned to him for the day, he finds having a day off when completely alone to be off-putting and depressing. Upon coming across and old boxcar and a battered volleyball, however, he discovers that imagination can make anything enjoyable.

A carnival arrives on Sodor and the roller coaster is leaving Percy in a very nervous fit, leaving Thomas, Nia, and Kana to help him get over his fear. When he goes through a number of lines likened to a roller coaster by his friends, though, Percy learns that a tough challenge can be prepared for by practicing it one part at a time.

On the day of a fireworks show, Yong Bao visits from China and performs a rescue, which leaves Thomas feeling jealous. The little blue engine sets out to prove himself braver with a dangerous stunt, but when he is joined by Yong Bao on a rescue mission, Thomas learns that bravery doesn't necessarily mean being fearless.

A bake-off is taking place at Vicarstown, and Thomas is tasked with delivering the necessary ingredients, but the journey is full of bumps and turns, causing many of the ingredients to become ruined. With Percy's help, Thomas puts into practice that some plans don't have to be taken from the start.

A paleontologist has dug up a T-Rex skeleton in the old mines, and the Biggest Adventure Club are tasked with delivering it. However, they arrive out of order, and the skeleton is incomprehensibly jumbled until they figure out how to maintain the order the pieces were left in.

On the day of a light festival on Sodor, the engines spur on and encourage a race between Thomas and Diesel, causing Thomas to break one of the fragile multi-colored lights. When he lies about it, he only feels worse, and learns from Gordon that being honest will always be the best way to do things.

Thomas, Nia, and Diesel lose a delivery of orange trees meant for a new plaza at Vicarstown, and have to hunt down replacement plants for the grand opening. On the way, Nia shows the others that there's always something amazing when looking close enough.

Nia has to help Thomas and Percy deal with an argument between the two, and teaches them that letting off steam can help cope with frustration.

The last day of Yong Bao's visit to Sodor comes much too fast for the other engines' liking, who are convinced he'll forget them without a souvenir. When they fail in this task, however, they learn that nobody is forgotten permanently, and that there will be other chances for Yong Bao to visit.

The engines are thrilled to be setting up for the Fall Festival- except for Thomas, who still pines for the summer season. With the help of the others, however, he learns that although it isn't his favorite season, fall still has plenty of fun for him to enjoy.

Thomas throws out Diesel's favorite oil can after getting his wheels greased, but when Diesel learns of this he becomes determined to find it. The search goes for several fruitless moments before the can is revealed to be safe, and Thomas learns that everything has sentimental value to someone; even an object that seems all but useless.

After Gordon ends up crashing, Thomas and Diesel have to take an important delivery to the docks. However, a friendly competition leads to Diesel losing a wheel, and the duo learn that not only is teamwork the better option, but a contest isn't fun when you take it too seriously.

While out near the farm, Thomas discovers a cowbell on the tracks and decides to share it with his friends, but quickly grows sour over it not returning. After the confusion gets cleared up, the others learn that while it is nice to share, it only works well when the borrowed object is returned in the end.

On the anniversary of Nia's arrival to Sodor, she plans on inviting everybody to a party, but to her disappointment everyone has seemingly forgotten about the occasion and are acting strangely. Eventually, she finds that they did remember and have been preparing a secret surprise party, and learns that things aren't always what they seem, especially on a special occasion.

Sir Topham Hatt makes a big ceremony out of the installation of a new bench, but it is so ordinary that the occasion seems pointless. He eventually tasks Nia with making a song about it on her suggestion, but it takes numerous thoughts before she finds something special about a normally mundane object.

Diesel is accompanied by Bruno while hauling a replacement light system for the Vicarstown lighthouse, but the pair struggling to communicate leads to both of them getting stranded in Crumble Canyon, with cooperation being their only hope of getting out.

On the day of the Vicarstown "Fish Day" event, Nia is determined to get there fast, but it ends up frightening the fish. With the help of Kana, she realizes that even if you go slow, being smart always helps in reaching a destination on time.

Thomas is determined to make a lasting impression for Ashima on the first day of her visit to Sodor, but to his annoyance his plans always fall apart in practice. When they settle on an improvised plan, Thomas learns that nothing has to be particularly grandiose to leave a good impression.

Sandy gives Carly a brand-new electromagnet to help in their job of assisting Tess in unloading Bulstrode at Kellsthorpe, but when he arrives early, Carly is forced to learn on the job. Despite the restrictions of Tess's impatient behavior, Carly learns that mistakes are a natural part of learning, and nothing to be dwelt upon.

Thomas and Percy have to deliver a hot air balloon to a festival at Norramby Beach, but after unexpected obstacles force the balloon to prematurely inflate, it snags up Percy and sends him skywards, forcing Thomas to coordinate a team rescue effort. The pair also learn that even the unexpected can be enjoyable once you let it go with the flow.

When a brand new line is being built as an extension to Cronk, Thomas and Percy's eagerness to take a ride on it gets ahead of themselves, resulting in the two engines getting stuck in the mud. After spending the whole night stuck, they learn that when you take a closer look at things that you have already seen before, they can be truly amazing.

When the Christmas tree is unable to be delivered, Thomas, knowing how important traditions are to Bruno, looks around the island for a replacement tree. When they can't find one, the engines work together to decorate Lookout Mountain into the ultimate Christmas tree.

Thomas, unable to accept Boxy is old and has run his course, tries to find a way to fix him, however fails. Together with Carly, Sandy, Percy, and Whiff though, Thomas is able to rethink his plan and make Boxy good as new!

When Sir Topham Hatt predicts a snowfall on the island, he assigns Thomas, Percy, and Diesel to deliver supplies to the lighthouse. When Thomas brings his shiny, blue snowplow, he carelessly plows everything in the engines' path, leading to the tracks being blocked by pigs. Upon learning that Thomas can use his snowplow to move the pigs out of the way, he learns that while it's good to have fun, you shouldn't let it distract you from an important job.

After finishing their last deliveries for the day, Thomas is shocked when Kana says that she needs some alone time to relax. He jumps to the conclusion that Kana is upset and he along with the other engines try many things to make her feel better. After many attempts from her friends to cheer her up including swarms of butterflies, train tag, and train washes, Kana becomes angry and shouts at her friends. Upon thinking that Kana no longer wants to be friends with them, the dismayed engines play a sad game of train tag. When finally getting some time to herself, Kana notices that there is a storm coming and fears that her friends will get caught in it. She quickly finds them and gets them to safety in a nearby tunnel just in time. After her friends take a bit of time to listen, Kana teaches them that while having fun is always nice, it's always good to emotionally recharge and appreciate the quiet things in life sometimes.

When Whiff gives Nia the task of delivering a big earth ball to Norramby Beach, she completely plans out the route she is gonna take and thinks that the job will be very easy. She is soon proven wrong, as her plan is disrupted by a boulder runaway at Crumble Canyon. She goes to Lookout Mountain to try to find a better route, but all of the lines that go towards the beach are blocked. Something completely unexpected happens when the straps on her flatbed snap and the earth ball bounces around all over the island. Nia tries her best to catch it, but it is no use, after talking with Thomas and taking help from Skiff, she learns that sometimes you just have to go with the flow, rather than sticking to a specific plan.

It's Valentine's Day and Percy is determined to get the valentines mail delivered all around the island. Despite the large amount, he manages to get all of his deliveries done, alongside taking some additional requests from his friends. Trouble soon arises for the green engine, as him not paying attention to the tracks results in all of his friend's gifts getting sunk into the mud. In the words of a song though, him and his friends learn that most gifts should come from the heart, rather than a box.

It's Plant-A-Tree day on Sodor and Sir Topham Hatt assigns Thomas, Percy, Nia, Kana, and Diesel to deliver trees all over the island. There is soon a problem though, as Bulstrode shows up carrying a huge tree that Gordon was supposed to take along with his other tree deliveries. Hearing that the delivery will make them known as famous, Thomas and Diesel decide to compete, whoever gets their deliveries done first will be who gets to take the big tree to Vicarstown. The two race all around the island, causing mayhem everywhere, in the end, Thomas wins the big tree delivery. Diesel follows so that he can take over if Thomas messes up. They try all the routes to Vicarstown but none work as the tree is too tall. The eventually come to a steep mountain, but with the windy weather the tree falls over knocking both of them off the tracks into a mud pit, even Carly and Sandy who had come along and tried to help. Thankfully, Beresford comes to their rescue revealing that he was following them to see if they needed his assistance. With his help, they get the tree delivered on time, and Thomas and Diesel both learn that you should always try to focus on your strengths, rather than your weaknesses.

The boys choose to take in a lamb from the farm for the evening, but this becomes chaotic for Diesel when the entire flock joins them at the sheds. Once everything is sorted, the engines learn that interacting with animals can

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.

A potentially fun day gets ruined for Percy when an overly-competitive Thomas and Diesel force him to be the judge in all of their competitions. Eventually, he snaps under pressure, having had enough of the pair's poor sportsmanship. After making up, Thomas and Diesel learn that poor sportsmanship can ruin the days of more than just the competitors of a competition.