"The mist is too thick."

"I can't see anything."

"How can we find Thomas in this."

...

"Thomas!"

"Thomas, it's good to see you."

"Thomas, you're alright!"

...

"Edward!"

Edward blinked, his memory interrupted. "Hmm? Percy you startled me!" He exclaimed, looking down at the little green tank engine.

"Sir Topham Hatt wishes to see you at Knapford." Percy said, practically bouncing on his wheels. "He says he's got a special's special for you!"

"Well, I best be on my way then." Edward whistled to Percy as he hurried away.

Percy watched him go, returning his friend's whistle. He was unable to stifle his worry. He had never seen Edward so, distracted. The elder blue engine had been this way ever since they'd rescued Thomas from Misty Island. Percy looked at the long lines of freight cars in the sides, waiting to be shunted.

"Well, back to work." He sighed but he was still worried.

...

Later, Thomas steamed in. "Hello Percy!" He whistled.

But Percy didn't answer. He was still shunting cars with a distant look on his face. Thomas whistled again and this time Percy jumped. "Oh, hello Thomas." He greeted.

"What's the matter Percy? You look worried." Thomas asked.

"It's about Edward." Percy sighed. "Have you seen how distracted he's been lately."

Thomas was silent for a moment. "Yes," he said slowly. "I have. It's been bothering me too actually."

"Maybe you should talk to him about it?" Percy suggested.

"Why me?" Thomas asked, surprised.

"Because he's only been this way since you returned from Misty Island. I think it might be connected somehow." Percy replied.

"Hmm, maybe you're right Percy." Thomas agreed and hurried off to fetch Annie and Clarabel for his next train.

Meanwhile, Edward was steaming along the mainline. Sir Topham Hatt's special was a group of college students hoping for a grand tour of the island. They'd been riding trains all day and Edward was meant to take them to Brendom Docks so they could catch the next ship home.

As he chuffed along, he allowed his mind to wonder again. The day they found Thomas was a joyous one. He couldn't think of any words to describe his feelings when he saw his student chuff around that misty corner in Echo Valley. But that feeling was tempered by the knowledge of just how close they had all come to never seeing that again. Thomas easily could've derailed in that misty hell and no one would've known where he was or even if they could help him if they did find him. Edward still shuddered to think about what might have happened. He was still thinking when he pulled into Brendom.

Edward was so distracted that he didn't see Thomas on the other side of the tracks.

"Edward. Hey Edward!" Thomas began but Edward was already steaming off. "Bother." The tank engine muttered. Once his passengers were let off he steamed out of the docks as fast as his driver would let him, determined to catch up to the larger engine.

On the way he met James at a junction. "What's got you in such a hurry Thomas? Running late again?" The red engine teased.

Thomas only half-pouted. "No." He replied. "It's Edward. I know something's bothering him and I'm trying to find him so I can talk to him about it. But he keeps getting away."

James sighed. "He's letting his thoughts run away with him again. A bunch of 'what if' scenarios. He does that sometimes Thomas. Just let him be. He'll come around."

"But, I know it has something to do with me. He's only been like this since I returned from Misty Island." Thomas protested.

"Not quite. He was like this when you were on Misty Island as well. But it was worse then, much worse." James began. "You were missing three days Thomas and in those three days he didn't work. Not once."

"Not at all?" Thomas was shocked. Out of all the engines, Edward had the strongest work ethic. He was always out doing something from dawn to dusk and sometimes later than that. And he'd instilled a similar attitude in Thomas who was always determined to carry out a job.

"Oh he didn't stay in the shed but the rest of us had to pick up his jobs while he went around the island looking for you. I don't think there was a single branch line and siding he missed." James replied.

"He spent that whole time, looking for me... Why didn't he say anything?"

"Because he doesn't want you to feel guilty. Even if you could've waited for another ship once you were on that platform there's nothing anyone could've done." James said. "Now only if someone could convince him of that." He added in a mutter.

"What?" Thomas questioned.

"He blames himself, Thomas." James replied.

"How can he blame himself? He didn't do anything?!"

"Exactly!" The red engine exclaimed. "He feels he should've said or done something that would've made you stay and wait for the next ship. Or maybe he could've figured out where you were sooner."

"But that's not fair!"

"No, it isn't. But that's just how he is."

The signals turned green and James huffed away, his line of goods cars following behind. Thomas sighed and followed at a slower pace more determined than ever to talk to Edward.

...

Thomas finally met up with the old engine on the way back to Tidmouth.

"Hello Thomas." Edward greeted him warmly.

"Hello Edward." Thomas whistled back.

"How was your day?"

"Fine." Thomas paused. "Um, Edward?"

Edward could see the worry in his student and slowed his pace. "What is it Thomas?" He asked gently.

"Can I ask you a favor?"

"Of course, what do you need?" Edward's tone remained as kind as ever.

"Can I ask you to stop blaming yourself for my disappearance."

Edward was so shocked he stopped on the spot. Thomas shot past him a ways before backing up beside him. The little tank engine didn't say a word as he looked at his mentor. Edward was silent for a few minutes, then he sighed. "You were the first engine I'd ever trained Thomas. When Sir Topham Hatt first gave you to me it was a huge responsibility. One that I feel I still bear."

"I'm much bigger than that now Edward. I make my own decisions." Thomas said.

"Decisions that have been partially shaped by my teachings." Edward retorted. "If you had been on Misty Island when you first got here, how would you react?"

"I think I would've been too panicked to do anything right." Thomas said slowly.

"Mm hmm. And you did the exact opposite now. You thought about what you needed to do first. Sure you made a few mistakes but remained calm throughout." Edward said.

Thomas could understand what Edward was saying, even if he didn't like it. "It's still not your fault." He said. "Why do you feel like it is?"

"It's just how I am, Thomas. I can't help that." Edward replied with a heavy sigh. He really didn't want to have this conversation but Thomas wasn't giving him much of a choice.

Thomas edged forward slowly, carefully considering his next words. Another thing Edward had helped teach him. Think before you act.

"I forgive you."

Edward was surprised, his eyes snapped around to look at the engine beside him. "What did you say?" He asked quietly.

"I said I forgive you." Thomas repeated, looking his mentor in the eye. "Because you're right. You did teach me how to react in certain situations and maybe you could've convinced me to wait for the next ship but chose not to speak up. And for that, I forgive you Edward."

Edward closed his eyes, taking a deep breath and when he opened them again his gaze was soft as he gazed at his student. "Thank you, Thomas. Thank you."