Henry Green wasn't exactly having the most pleasant of days.

The damp, rainy weather of London and too many late nights researching had brought on a particularly bad cold. He thought he would be able to tough it out, and carry on with his work … but as he sat silently behind the counter of his curio shop, his energy levels began to slowly drop as he watched with glazed eyes as his associates, the Frye twins, argued heatedly in front of him.

"This is like that one time back in Crawley," Evie said with a scowl. "Do you remember, Jacob? You crashed a wagon into the side of Farmer Duncan's shed. A whole wagon, Jacob!"

Jacob threw his hands up in the air, exasperated. "How was I supposed to know that those old mares could move so fast? I had to do something to stop the Templar shipment, Evie. Unlike someone else, who spent the whole day cooped up in her room reading books."

"I was researching!"

Their raised voices and the strained tension in the air caused a dull throbbing pain to develop at the back of Henry's head. His mind was entirely in a dull fog, like an opium smoker's. He couldn't even remember what the twins were arguing about.

"What do you think, Henry?" Jacob suddenly prompted, and the twins turned to look at him. Their expectant gazes either meant they wanted him to take a side, or to play peacekeeper and facilitate a compromise between them.

But Henry knew the beginnings of a migraine when he saw one. He merely said quietly, "I'm sure the both of you can work this one out by yourselves."

"But Henry –"

"Evie's the one not making sense here –"

He stood up from behind the counter. This sudden movement caused the Fryes to momentarily fall silent as they watched him.

"Is something the matter, Henry?" Evie asked, sounding concerned. But there was a certain tone in her voice and the way she glanced shortly at Jacob that suggested she wanted Henry to take her side, this time.

But Henry was beyond taking sides. He merely muttered, "I'm going upstairs to take a short rest. You two can stay for as long as you like, but if you are leaving, please do help me lock up."

He slowly ascended the stairs that led to his apartments above the shop.

Downstairs, the twins could only exchange sour glances.

But before either could say another word, there was a sudden crack of thunder, and the bleak grey skies emptied and it began to rain drearily onto the streets of London.

If there was one thing that London has far too much of, Jacob thought as he stared desolately out the window, it's rain.

The rain was particularly thick; falling in heavy, relentless droves that turned the world into muddy swirls of blue and grey. It didn't look like it was going to clear up anytime soon.

Somehow, the dreary weather had somehow dampened the twins' tempers, and the both of them dropped their previous argument to fall into some kind of resigned truce. They accepted they were going to be trapped in Henry's curio shop until the weather cleared, and they might as well spend it in peace.

But Jacob was bored. He let out a long, audible sigh, and heard his sister tutter in annoyance behind him.

"What?" he asked, turning around and facing her.

Evie raised an eyebrow from where she was sitting in the corner, curled up with a book she had somehow fished out from the shop's many shelves. "That's the third time you sighed in the past five minutes, Jacob," she said. "There's nothing we can do about the rain. Sit down, please."

Jacob frowned, making no effort to hide his boredom. It was easy for Evie - she thrived on rainy days, being able to sit quietly by herself for hours on end, settled contentedly in a nest of books. But Jacob felt trapped in the little shop, and he began to pace restlessly.

"Evie, let's call for a carriage," Jacob said helplessly.

"You know there won't be a carriage in London that would come out in this rain," Evie said, not bothering to look up from her book. She slowly turned a page. "I told you to bring umbrellas. This is what you get for not listening to me, Jacob."

Evie did not need to look up to know that Jacob was scowling at her. She heard him mutter audibly under his breath, "Assassins don't need to carry umbrellas, we have hoods." But even so, he made no attempt to step out into the downpour.

Jacob looked around, dying for a distraction. "Where's Greenie?"

"Mr. Green's upstairs in his room," Evie said with a sigh. "I suggest we don't disturb him, Jacob."

"Are you still calling him, 'Mr Green'? Even now that we know his real name is 'Jayadeep'"?

At the mention of Henry's real name, Evie glared up at Jacob and her cheeks coloured slightly. "Well, you're still calling him, 'Greenie'."

"It's a term of endearment," Jacob explained, grinning. "I'm sure you have your own nicknames for dear old Mr. Green – what do you call him now? Sweetheart? Darling? O light of my life, fire of my soul – "

"Sit down quietly Jacob, I'm trying to read," Evie said firmly, the rosy shade of red that had risen to her cheeks now reaching her ears.

Jacob began to pace again, but he had quietened down. He recognized that tone of voice meant Evie was in poor temper and in no mood to entertain him. Fine, then – he would have to find some entertainment on his own.

He looked about Henry's curio shop. It was indeed full of small curiosities and random knick-knacks arranged in apparent randomness across the shelves – strange gold statues from India, wall-paintings from China, globes and spyglasses and pocket watches and brass instruments from distant ends of the Empire. Jacob picked up a delicate Arabian perfume bottle and pulled out the stopper to sniff the contents, raised an eyebrow, and put it back. He flipped through a stack of books, all of which were in German. As he slowly made his way to the back of the shop, he noticed a thick curtain hanging over a small discreet doorway, and his eyes lit up.

"Evie, Evie," he called in a loud whisper, "I think there's a hidden room back here!"

He choice of words had their desired effect – Evie glanced up from her book and peered into the shadows where he was standing. "What hidden room?"

"Did Greenie ever lead you to his secret back room?" Jacob said, with added relish. "Look here – nothing says, 'secret hidden room' like a conspicuous red velvet curtain, don't you think? Who knows what mysteries could be lurking in Henry Green's secret dungeon lair –" here his voice took a theatrical turn – "Henry Green, the enigmatic man formerly known throughout London as 'The Ghost'?"

To Jacob's delighted triumph, Evie put down her book and got up from her chair and strode to stand next to him. She peered at the red velvet curtain, and Jacob knew she was looking at it through her eagle vision.

"There's a door," she said, tentatively, "that leads to some stairs that lead underground."

"Oooh, mysterious." Jacob stepped closer to the curtain. "Shall we?"

Evie looked doubtful. "Jacob, it's disrespectful to go snooping around Mr. Green's shop without his permission –"

"Oh come on, Evie. Like you said, he's upstairs, preoccupied with a migraine. How often do we get a chance like this? Just a quick peek – he wouldn't even know we've been down there."

Evie bit her lip and hesitated for a split second, before she relented with a sigh. "Fine. Just a quick peek, alright?"

Jacob pulled the cord that drew back the curtain. The stairs that let below ground curved to disappear into a darkened basement room. A quick look in eagle vision showed that the room below was unoccupied, but the ghostly shapes of items of interest danced like lantern-fire behind their eyes. Jacob exchanged a glance with Evie and saw she was just as excited as he was to explore the basement they had been unaware of until then.

Slowly they descended into the gloom.

As their eyes adjusted to the darkness, they could see it was a basement just below street-level, with a small window that opened out into the street. Faint light filtered into the small, darkened room, casting a soft, silver glow onto furniture covered in white canvas sheets, dusty crates, steam trunks, and shelves stuffed with books and stacks of paper.

Jacob found a box of matches and a candle, and lit them to cast more light into the room.

"This is fascinating," he murmured looking about the room with a wide, satisfied grin on his face. He looked towards his sister, and saw that she was already leafing through the books and rolls of canvases scattered about the room.

"These are from France," she said, in an excited whisper. "They date back to the 1700s! Jacob, look – these seem to be floor plans of a Parisian café –"

Jacob set the candle down on a steam trunk and pulled a heavy canvas cloth off a piece of furniture in the middle of the room, sending a cloud of dust flying into the air. Evie's eyes widened in panic and she whispered quickly, "Jacob! What are you doing? Henry's going to find out we've been down here –"

"Evie, it's a piano," Jacob said, smiling guilelessly at her. Indeed, an old upright piano stood in the middle of the room, looking as if it hadn't been touched in years. Its keys were yellowed with age and the wood paneling looked cracked from moisture damage. "How do you think they managed to get a whole piano down the stairs and into this little room, Evie? Now that is a mystery!"

Evie frowned. She knew Jacob was trying to distract her with a puzzle, but she couldn't help it and the cogs in her mind started spinning away. "It must have been carried down in pieces and assembled down here – probably the previous owner of the shop wanted to practice their piano-playing away from where people could hear."

Jacob circled the little piano, and Evie realized with cold dread what he was going to do.

"Jacob –!"

He pressed a piano key, and low, mournful note sang clearly in the air, hovering above the muted drumming of rain.

Evie and Jacob tensed, quickly glancing up at the stairs for any sign of movement or noise. They were met with several moments of uneventful silence. Evie breathed a sigh of relief, then threw Jacob a harsh glare. "I'm heading back upstairs," she announced, turning to go, "before Henry finds us."

"Suit yourself," Jacob answered, trying to sound cavalier as Evie made her way upwards. "Wait a moment," he said, "this is an Assassin's house, isn't it? What did you discover about pianos in Assassin houses, Evie? Like at the Kenway Mansion?"

Evie stopped in her tracks and groaned inwardly. She knew Jacob was baiting her, but she could already feel her curiosity bubbling over at the back of her head. The moment she and Henry opened the secret room in Edward Kenway's mansion was one of the most thrilling moments of her life – next to actually seeing a real Piece of Eden with her own eyes, of course. Ancient mysteries were one of her weaknesses, and she did not appreciate how Jacob took advantage of it.

She threw a mournful, conflicted glance at Jacob, who smiled innocently back. In a conspiratorial whisper, he continued, "You said it yourself: This piano was put here, where people cannot hear it being played. This room is probably soundproof, being underground. It's worth a try, isn't it?"

Evie sighed in defeat. How does Jacob do it? Ever since they were children, Jacob had a way of getting into trouble, yet Evie always found herself somehow being part of that trouble, and getting them out of it. With withering regret, she made her way to the piano, and Jacob laid down a packing crate in place of a chair.

She tried the opening notes from 'Lowlands Away', one of the sea shanties that she had picked up from exploring Edward Kenway's mansion – no effect. Of course. She expected as much. She looked about the room for any clues, and caught sight of Jacob picking up a dusty violin out of a dark corner of the room.

Evie merely stared at him, as he plucked at the strings. "And when was the last time you actually played a violin?" she asked, raising a skeptical eyebrow. She doubted he remembered anything from their musical training in their youth.

"About two weeks back, actually," Jacob answered smugly. "We celebrated another glorious victory for the Rooks at the Boar's Head, and one of the lads brought a fiddle and asked me to play. I'm not as rusty as you think I am, dear sister."

Jacob indeed had the aptitude and quickness for the violin – he picked up tunes and melodies almost effortlessly, but lacked the patience and attention required for true mastery. Once he'd learned enough for his own satisfaction (limited to popular tavern songs) he'd quickly lost interest in the violin and neglected all practice, while Evie diligently continued her training on piano alone. Sometimes she missed playing duets with him, but that was a long, long time ago.

She raised an eyebrow, still doubting. "Oh?"

With a smug smile, Jacob tucked the violin under his chin, and drew out a few long, haunting notes. Evie instantly recognized the tune, and, like clockwork, her fingers immediately danced out across the piano keys in accompaniment. The piano was slightly out of tune, being untouched for so long, but the melody carried out and soon the small room was filled with a sweet, melancholy song from their childhood.

The twins exchanged a glance, and without having to say another word they kept on playing to the song's eventual finish, and then grinned delightedly at each other.

"I haven't heard that song since we were … what, twelve?" Evie said with a small laugh. "I'm surprised you still even remember how to play it."

"I'm full of surprises," Jacob answered, beaming at Evie proudly, but just then he was interrupted by the soft sound of clapping coming from the stairs.

Their heads both whipped around to see Henry Green, leaning on wall, applauding their performance.

"I did not expect such musical talent from the Frye twins," he said, smiling. "Perhaps George was right in proposing you both appear in performance in Convent Garden."

Both of the twins must have had such looks of unguarded shock on their faces, because Henry burst out into laughter immediately after. "Two Master Assassins, taken by surprise? Well, they did not call me 'The Ghost' for nothing, you know."

"Henry, I am so sorry," Evie began, sounding mortified. "We – that is, Jacob –"

"We thought we could sneak in and sneak out without you noticing," Jacob offered, cheerfully, meeting Evie's murderous gaze with an affable one of his own. "Come on, Greenie, why didn't you tell us about your secret hidden room?"

Henry smiled and shook his head. "It's more of a basement of old knick-knacks than a hidden room," he admitted. "Occasionally things that don't get sold in the shop get thrown down here to gather dust. It's good that you have given them a new lease on life."

He reached out and touched the surface of the piano. "You are a wonderful pianist, Miss Evie," he said. "I'm glad I could hear a sample of your playing."

Evie smiled back, pleased with this praise.

But at that moment, Jacob stepped forward. "And what about me? Do you think I'm a good violinist, Greenie?"

Evie threw Jacob another withering glance, but Henry merely chuckled. "It's evident that music is in the Frye blood."

"How are you feeling?" Evie asked, concerned.

Henry shook his head slightly and smiled. "Much better, now that the rain has cleared up."

It was true – the heavy drone of rain had stopped, and they could hear footsteps and carriages rumbling past on the street outside. The twins exchanged a glance, and in the silence between them, it was clear neither wanted to leave, just yet.

Jacob grinned brightly at Henry. "Would you let us stay for tea?" he asked, in confident tones.

Henry chuckled. "If you could kindly indulge me with another one of your duets, I'd be happy to."

[AUTHOR'S NOTES: The musical duet I imagined the Frye twins playing is "Bloodlines", from the Assassin's Creed Syndicate soundtrack, originally composed by Austin Wintory. ;) ]