Cornwall had been caught in an unexpected cold snap, and with it came fog and snow. Fog is a nuisance for operational reasons, as it tends to gather in valleys and makes seeing where you're going rather difficult. As a result, extra safety measures had been put into place to ensure the trains could continue to run smoothly.
Charles and Zipp were making their way up the line to Truro one misty morning when suddenly an explosion echoed under Charles' wheels. "That was a loud one!" Charles commented. "There must be trouble up ahead."
"Sounds that way," Zipp replied. "That, or Cyril is out and about."
Cyril is a local fogman and safety inspector, whose job it is to keep the railway safe. Whenever anything dangerous looms, he places detonators on the track to warn engines to slow down. Usually detonators are use to signify that there is something on the line, but they can also be used to indicate caution.
Rather against character, Charles slowed down as he approached the fog bank. "Thank you, Cyril," he said.
"No problem!" Cyril replied. "Drive safely and carefully today!"
Zipp nodded. "Something's still not right around here," she said, as Cyril rolled out of earshot. "What Misty told us in the hospital is still concerning me. There's this woman trying to find us and steal power? What could she be doing that for?"
"To become more powerful?" Charles suggested.
"Well, that's rather obvious," Zipp replied. "I wonder if she was the person Awdry was warning about? Having said that, I have my doubts about Misty's honesty seeing as she happily lied to our faces."
"Did she 'happily lie', or was she coerced into doing what she did?" Charles offered.
"You seem to be in an oddly contemplative mood today," Zipp said.
"It's the fog. Reminds me of the day I was withdrawn. Nearly didn't make it either."
Later that day, the engines and their drivers had gathered at the shed for the unveiling of a new device Argyle and Lord Haven had developed.
"What is it?" Porter asked. "It looks like a grey box with a big noisy thing attached to it!"
"Anybody thinking of vuvuzelas?" Sophie offered.
"No," Pipp said. "Those things ruin the vibes of a positive morning stream. Mom says they became all the rage after the World Cup a few years ago, and she still hasn't gotten the noise out of her head."
"It's a mechanical foghorn," Lord Haven explained. "It's a horn designed to warn people and engines of fog being ahead."
"How does it know when fog is ahead?" Salty asked. "It has no eyes!"
"It uses data from the Met Office to trigger the siren," Argyle explained. "Here's a quick demonstration." He tapped something into the touchpad on the top, and suddenly the siren blared into life, making an incredible racket. After a few seconds, Argyle turned it off.
"That's loud!" Izzy said.
"It needs to be," Porter said. "How else would anybody hear it otherwise?"
"It's far too loud in my opinion," Sophie said. "That'll wake up anybody within a ten mile radius!"
"And," Charles chimed in, "it sounds like a canal boat. And I dislike canal boats."
"Why do you dislike canal boats?" Sunny ventured.
"Because canal boats are stupid and slow! They can't go any faster than four miles an hour! If you can't travel anywhere at a reasonable speed then what's the point?"
"And what of Cyril?" Hitch asked. "He'll be out of a job!"
"He's being used in conjunction with the foghorn for safety reasons."
"Isn't Conjunction junction a rail junction somewhere in the United States?" Rebecca ventured.
"That's an obscure reference," Ray noted.
But Zipp was concerned. This sounded like it didn't have enough failsafes to work properly.
The next day, Sophie and Pipp were making their way up the line when they were accosted by the blaring of the foghorn.
"That nearly knocked me out of my chair!" Pipp said. "I know haunted houses rely on sudden loud noise to scare people, but not this! I'm not really in the mood for scaring."
"I know," Sophie said. "Perhaps use the horn in a remix? Still, could be worse."
Neither of them commented on the fact the set ended behind them as they ran up the valley.
Unfortunately, Sophie was right. It could be worse. And it soon was. Up on the hills were a series of fences, designed to hold snow back. But the foghorn had been so loud it had disrupted the snow, causing it to shift. It broke through the fence and slid down the hillside, pooling down below on the track.
And the foghorn was buried under the snow as well. Further down the line, Charles began his journey, and before long was beset by thick fog.
"Where are we?" he asked. "This fog is making it impossible to see!"
"Something's wrong," Zipp said. "Why didn't the foghorn warn us?"
Suddenly, something huge and white loomed out of the distance. "AVALANCHE!" Charles shouted. "Brakes! Brakes!"
Zipp put the brakes into emergency, but it was too late. The heavy train had no chance of stopping in time and smashed into the snow, derailing the engine at the front.
Zipp dropped out of the cab with a shovel. "You OK, Charles?"
There was a moment's silence. "I couldn't be better. What do you think? And more importantly the line's blocked. We need to warn other engines!"
"And I don't exactly have any red petticoats on me either," Zipp replied. "We could really do with Cyril's help."
"Did somebody call?" said a voice, and before long Zipp saw Cyril walking towards her.
"Thank the stars you're here!" Zipp said. "That foghorn didn't warn us."
"It wouldn't, buried under all that snow," Cyril sighed. "Never trust any level of fangled technology, that's what I say." He handed her some detonators. "Place these at approximately sixty foot intervals, and turn on a torch so other people can see you."
So, off they went, laying detonators down onto the track. They were just in time, as not long after Zipp had placed the final detonators a whistle echoed in the distance. "Sounds like Rebecca's on her way."
Rebecca rolled along the line, humming to herself when suddenly-
BANG!
"That was a detonator!" she called to Hitch. "There must be fog or an obstruction up ahead!"
"Right, ahead slow," Hitch replied, and reduced speed accordingly. When they reached the third detonator, he brought Rebecca to a stop.
And it was good he did too. "Good grief!" Rebecca said. "Look at that snowdrift!"
"We'd best help clear it," Hitch said. He picked up his radio. "Mark, can you ask the passengers whether they'll help clear the snow?"
Quite a bit of shovelling and rerailling later, the line was clear once more. "Thanks, Cyril," Charles said. "I owe you one."
"No problem," Cyril replied. "I'll continue to be on duty here whilst the fog is a problem, then hopefully operations can return to normal. Clearly that foghorn wasn't as reliable as they'd hoped."
And he was right. Accidents do happen, but the engines know that as long as Cyril is watching over the line and warning them of fog, then there is nothing to fear at all.