Late on night on the Island of Sodor, Percy was at Knapford Station getting ready to take the mail train with Thomas, who was pulling a second train.

"There sure is a lot of mail tonight", Percy said, "I'm glad you were able to help me out tonight, Thomas."

"That's what friends are for, Percy", Thomas said, "besides, it's been a while since I pulled the mail train with you."

Pretty soon, the mail was loaded into the two engines' mail vans, and after their conductors blew their whistles, the two engines set off, with Thomas going down one route, and Percy going down another one.

"Alright", Percy said, "let's get these parcels delivered."

The mail in Percy's vans were organized in a certain way so they would be unloaded in the order of each station Percy stopped at, which he had a certain order of doing so, and as he puffed through the night with his mail vans, he made all of his deliveries on time, and was soon on his way to his last few stops.

"I'm making great time tonight", Percy said, "I wonder how Thomas is doing."

But Percy didn't realize that there was a fallen tree up ahead, and the signalman had dozed off and forgot to set the signal to red, and when Percy puffed past the signalbox, he saw the fallen tree on the line and panicked.

"Bust my buffers", Percy said.

Percy's driver applied the brakes, but it was too late, and Percy crashed into the tree and derailed, along with his mail train.

"Oh no", Percy said.

His driver and fireman had jumped clear before the crash, as did the guard in the brake van, and went to find a phone to call for help, and after a while, Edward brought Rocky to the scene of the accident and lifted Percy up off the ground.

"Don't worry, Percy", Rocky said, "everything's gonna be A-Okay."

"Thanks, Rocky", Percy said.

Percy's mail vans were severely damaged in the crash, but thankfully, most of the parcels inside them was unscathed, and Thomas had come so it could all be loaded into his mail vans for him to finish delivering for Percy.

"I can deliver this last bunch of mail for you", Thomas said.

"Thanks, Thomas", Percy said, "you're a true friend indeed."

Thomas blew his whistle and puffed away, and Percy was placed on a flatbed to be taken away to be repaired, but he was feeling worried.

"Who's going to pull the mail train for me while I'm being fixed", Percy thought.

The next morning, Sir Topham Hatt was in his office when he got the call about Percy's accident.

"Oh dear, that is terrible", Sir Topham Hatt said, "I'll see if I can find another engine to pull the mail train for the time being."

He hung up and sat down on his desk.

"Right, then", Sir Topham Hatt said, "let's see what we've got here."

Sir Topham Hatt pulled out a schedule book and checked to see which engines were available.

"Thomas is working on his branch line today, James has passenger duties, and Toby is working at the quarry with Mavis", Sir Topham Hatt said.

He checked to see what the other engines were doing that day, and found that many of them were already occupied with other duties.

"Oh dear", Sir Topham Hatt said, "it seems that finding an engine to fill in for Percy today may be harder than I thought."

Suddenly, an idea popped into his head.

"Actually", Sir Topham Hatt said, "there may be one engine I can turn to for help."

Sir Topham Hatt got into his car and drove to Knapford sheds, where he found Molly parked, so he got out and went over to her.

"Good morning, Molly", Sir Topham Hatt said.

"Good morning, Sir", Molly said, "what can I do for you?"

"I have an important job for you", Sir Topham Hatt said, "Percy had an accident last night while delivering the mail train."

"Oh dear", Molly said, "is he alright?"

"Yes, he's fine", Sir Topham Hatt said, "but he's at the works, so there's no one who can pull the mail train today."

"That's terrible", Molly said, "but why have you come here to tell me this?"

"Because, Molly", Sir Topham Hatt said, "with Percy unavailable and everyone else busy today, I was hoping you'd be willing to pull the mail train in his absence."

Molly was surprised by Sir Topham Hatt's request.

"Me, Sir", Molly asked, "you want me to pull the mail train?"

"Of course I do", Sir Topham Hatt said.

"Thank you, Sir", Molly said, "I promise I won't let you down."

"Wonderful to hear", Sir Topham Hatt said.

Sir Topham Hatt got into his car and drove away, and Molly smiled with excitement.

"Wow, the mail train", Molly said, "this is so exciting."

Molly left the sheds and went to the water tower to take on water, and when she got there, she found Thomas already there.

"Hello, Molly", Thomas said, "you look like you're in a good mood."

"I am", Molly said, "I'm taking the mail for Percy today."

"That's nice", Thomas said, "have you ever done a job like this before?"

"Nope", Molly said, "this is my first time doing this."

"Then you better ask Percy how he delivers the mail", Thomas said, "he knows all about this kind of stuff."

But Molly didn't want to ask Percy for help, and she felt like she could do it all by herself.

"No thank you", Molly said, "I'm sure I can figure it out on my own."

"If you say so", Thomas said, "well, I'd better go and collect my passengers."

Thomas puffed away from the water tower and Molly pulled up to it, and as her driver filled her up with water, she thought more about her important job.

"It's just delivering a few parcels", Molly said, "how hard could it be?"

Molly puffed away to collect the mail, and when she got to Wellsworth Station, she found Tom Tipper the postman loading parcels into some maroon open freight cars and one mail van at the back of it, much to her curiosity.

"I thought the mail was carried in vans", Molly said, "why are we using freight cars with just one van?"

The stationmaster walked up to Molly and explained the reason to her.

"Some of the mail vans were damaged in Percy's accident last night, and a few others are currently being used by other engines", the stationmaster said, "since we can't fit all the mail into one van, we've got to make do with some freight cars."

"Oh, that makes sense", Molly said.

Just then, Tom finished loading the mail into the van.

"There", Tom said, "all done."

Tom shut the van's door and walked over to Molly.

"You've got quite a bit of mail to deliver today", Tom said, "some of the parcels are for Farmer McColl, some are for the children's party at Maithwaite, and some are for the school."

"Okay", Molly said, "I'll get right on it."

Molly pulled out of the station to go and deliver the mail, and as she puffed along the line, she thought about where to go first, unaware of Percy's special order for delivering the mail, and eventually came to a decision.

"Tom Tipper mentioned Farmer McColl first", Molly said, "maybe I better stop there first."

Molly soon arrived at Farmer McColl's farm, and after the parcels were unloaded, she went off to her next destination.

"The next place Tom mentioned was the children's party", Molly said, "I'll stop there next."

When Molly got to Maithwaite station, the parcels were unloaded, and she puffed off to make her last delivery.

"Now all that's left is the school", Molly said.

Molly went to the school and dropped off the last of the parcels there, and after she did so, she puffed down the line feeling proud of herself.

"That was easy", Molly said, "I made all the deliveries without having to ask anyone for help."

But Molly didn't know that she had delivered the parcels to the wrong places, and it wasn't long before Sir Topham Hatt began getting phone calls about what had happened.

"I am terribly sorry about this", Sir Topham Hatt said, "I'll sort it out right away."

Molly pulled into Knapford Station and found Emily picking up passengers at the platform next to her.

"Hello, Molly", Emily said, "you look like you've been busy."

"I have", Molly said, "I've been delivering the mail for Percy while he's at the works."

"That's nice", Emily said, "how did it go?"

"I'd say it went pretty well", Molly said, "I stopped at every stop and delivered all the parcels right on time."

Just then, Sir Topham Hatt exited his office and walked over to Molly with an annoyed look on his face.

"Molly, I just received some phone calls about your mail deliveries", Sir Topham Hatt said, "it seems that you've delivered the parcels to the wrong destinations."

Molly was surprised.

"What", Molly asked, "that can't be right."

"But it is", Sir Topham Hatt said, "you delivered the parcels for the children's party to Farmer McColl, the parcels for the school were delivered to the children's party, and you dropped off the parcels for Farmer McColl at the school."

Molly was very upset to hear that.

"You must now collect the parcels and deliver them to the right destinations", Sir Topham Hatt said.

Sir Topham Hatt went back inside, and Emily decided to try and help Molly out.

"Maybe you should ask Percy for help", Emily said, "he'll know what to do."

Molly knew that Emily was right, but she still felt like she could figure out what to do on her own.

"No thanks, Emily", Molly said, "I'll figure this out."

Molly puffed away to collect the parcels and fix her mistake, and after picking them up from each stop, she thought about what she would do this time.

"I have to hurry and make these deliveries, or I'll be late", Molly said.

She began thinking about where she could stop first, but she couldn't make up her mind.

"Should I stop at the school first this time", Molly asked, "or maybe the party?"

Molly was so busy thinking that she didn't notice that a set of points up ahead were set to a closed track, and she ended up going down it and rolled right into a barrier, causing parcels to fly out of her freight cars and fly everywhere.

"Oh no", Molly said, "now I'll never get the parcels delivered on time."

Molly's driver and fireman loaded the parcels back into the freight cars, and as they did so, Molly thought to herself about her current predicament.

"I'm such a silly engine", Molly said, "I thought I could do this without anyone's help."

She now knew what she had to do.

"I'll go ask Percy for help", Molly said, "he'll know what to do."

Molly steamed off to the works to find Percy, and sure enough, there he was, still being repaired by the workmen.

"Hello, Percy", Molly said.

Percy was happy to see Molly.

"Hello, Molly", Percy said, "what are you doing here?"

"I need your help", Molly said, "can you tell me how to deliver the mail?"

"Of course", Percy said, "when I deliver the mail, I start at the stop that's the furthest away, and then I work my way back to Tidmouth Sheds from there."

"Is that so", Molly said, "that's a clever way to deliver the mail."

"Thank you", Percy said, "the mail's even organized so the right parcels are unloaded at the stations I stop at in that order."

"That explains why the wrong parcels got unloaded at each stop the first time", Molly thought.

Molly felt happy about asking Percy for help.

"Thanks for your help, Percy", Molly said, "I have to go deliver the parcels now."

"Okay", Percy said, "good luck!"

Molly hurried off to deliver the parcels, and since Percy had told her how to deliver the mail, she managed to deliver all the parcels to the right places, with the children at Maithwaite getting their parcels in time for the party, the right parcels were delivered to the school, and Farmer McColl got his parcels as well, and once it was all over, Molly made her way back home, now knowing the importance of asking for help when you need it.