A/N: I'm so sorry for the wait! I was planning to update for Dr. Moon for Doctor's Day; but I was floored by a heavy cold, and I also lost internet for over a week; both during my Easter break, too. I don't care what Stephen said about making your own luck; that was most definitely not the luckiest holiday I ever had.

Sorry for the rant, I just think that as soon as I get a holiday off, I fall ill with something.

So, without further ado, a very belated Happy Doctor's Day to all doctors everywhere- your amazing work is much appreciated by your patients; regardless of your speciality or field.

And behold, Chapter 53!

P.S. thank you, everyone, for helping me reach over 500 reviews! I cannot thank you enough for your support for this story. I am planning to wrap it up soon and publish the final story in the trilogy; 'Loyalty to Luke 3- On the Other Side of the Mountain.'

….

Luke had just reached the Main Terrace of the Quarry when he suddenly ran into Rusty, who was pulling a train of empty trucks behind him. They clattered and rattled as Rusty braked to a halt.

"Hello, Luke! What's the hurry?" He asked in surprise, looking at his now red-faced companion. Luke, however, didn't acknowledge his friend's greeting.

"Hey, Rusty, have you seen Duncan?" he asked, hopefully, without stopping for breath. Rusty raised an eyebrow.

"No, I'm afraid I haven't seen much of him this morning- in fact, I haven't seen him in this past hour or so. But I'm sure he couldn't have gone far." The little orange diesel replied, frowning. "Maybe he had another job to do for either the Thin Controller, or Mr. Bailey."

"Maybe." Luke agreed. "But surely he would have said something to us if he wasn't going to be here."

"Duncan's a tad…. Erm, unpredictable." Rusty replied. "You can never tell what he'll say or do next. But there's always one constant about him; his grumbling." He cracked a smile; but Luke didn't return it.

"He hasn't even been grumbling the past few days…" Luke observed worriedly, gnawing at his lip. "Rusty, is depression catching?" he asked suddenly.

Rusty was caught off guard by the question; but fortunately, he was able to formulate an answer on the spot. "Well, it's not catching, so to speak- but mindsets can sometimes rub off on others." He explained. Then, to make Luke feel a bit better, he added, "I think it's because he has something on his mind. Whether it's about you or something else I can't tell you."

Then, from behind the pair, they heard a voice, "Ah, welcome back, Duncan! How was your run?"

"That sounds like Mr. Bailey," Realized Rusty. "But where did Duncan go?" He wondered, turning back to Luke; who had a horrified look of realisation on his face.

"What's the matter?"

"Dr. Moon- I forgot!" Luke answered, his Irish brogue up an octave in worry and distress. "It's been a week since my last appointment!"

"Oh, it has!" Rusty agreed, realization sinking in like boots in cement. "A word of warning; you might want to talk with her out of sight, just in case. We don't know when Paxton will return to the quarry, Luke. He could take ages at the docks; but the Thin Controller keeps warning him about being tardy, so he'll try to come back here quicker. As much as I hate to say it to you, I strongly suggest you return to hiding as soon as you can."

"Right."

….

Skarloey had been on his way to apologize to Rheneas for earlier when he and Mr. Bailey saw Duncan returning with Doctor Moon, now crowned with a hard hat. for Luke's next therapy appointment. Now, looking at the Skarloey Railway's No. 6, Skarloey noticed that Duncan looked like he had very little sleep the night before.

"Hey, Duncan," he said quietly, causing the younger engine to look up at him. Skarloey gave an encouraging smile; to which Duncan managed a very, very small smile in return.

"Hallo, Skarloey," He whispered.

"What's wrong, Duncan?" Skarloey continued gently, who was feeling worried about Duncan and his recent downcast mood. He wanted to comfort Duncan; but he didn't know what to say; so, he hoped Duncan could confide in him.

But before Duncan had a chance to say something, Rusty and Luke arrived to see him.

"There you are, Duncan!" Luke exclaimed in relief. "We were worried about you. I wanted to talk to you"-

"Might it wait until after this session?" Dr. Moon interrupted coolly. "I understand you do have other matters of concern, Luke, and I regret to interrupt you in the middle of addressing said concerns; but I have a packed schedule this week, and we must use this time wisely." She said.

Luke was about to protest this, but on seeing his therapist with her hands on her hips, foot tapping patiently on the rock floor, made him nervous and he quickly changed his mind about arguing with her.

"Duncan will be fine," Said Skarloey reassuringly to Luke, before looking over at Duncan. "I'll help you out, boyo- you look like you need a helping buffer." He added kindly.

"Thanks," Duncan said with a pained smile. "I'd… I'd appreciate that. I know I do slack off sometimes, but I genuinely feel pretty sluggish today."

"... I'll help you with the trucks, and you can tell us what's bothering you." The old engine answered gently. "Come along."

With that, the two engines left. Mr. Bailey went to investigate how Rheneas was getting on with Owen before returning to his office, and Rusty had to return to work.

That left Luke with Dr. Moon.

"I'm guessing you'd rather be back in the tunnel again for this session." Moon said dryly, looking around at the bustling engines; now flashes of colour against the blue-coloured rocks in the bright sunshine.

"…y-yes, ma'am…" stammered Luke nervously, glancing towards the quarry entrance to see if Paxton had returned to the quarry yet; only letting a small sigh of relief escape when he saw no sign of the big diesel.

"Very well- in which case, lead on, Luke." She announced, gesturing towards the nearest tunnel with her perfectly manicured hands.

"It might be easier if you join us on the footplate," Geoffrey cut in, before Luke could start on his way "It's hardly a clean place to be in, of course, but it'll save you a walk over."

"Quite." Dr. Moon agreed, climbing aboard Luke's cab. "You know," she added nonchalantly, shifting herself round to give both herself and Luke's crew some space. "It's probably none of my business to say such a thing; but your cab is very cosy."

"Thank you," Replied Luke, feeling confused by that comment. However, realising that he couldn't afford to waste more time, he reluctantly set off towards the tunnel.

….

He felt saddened and disappointed; as grateful as he was for Dr. Moon helping him, especially with his situation, he had hoped he wouldn't get another appointment until after today; because he certainly didn't want to spend St. Patrick's Day talking about his feelings; especially not about what he told her last time.

Now Duncan was feeling down about something, and Luke could feel the doubts arise in his smokebox from its ashes, like a phoenix.

And he still never got to wish Duncan a happy St. Patrick's Day.