Sherlock was not at all admitting that he felt substantially better after having eaten, because once that kind of thing got out, there would be no stopping John and his ideas about regularly scheduled meals and calories counts and balanced nutrition. It was, after all, just an anomaly that eating during a case actually helped his thought processes. And it was only because he'd suffered that concussion the previous weekend that there was any kind of deviation in the pattern at all.
He felt satisfied with this explanation and was able to ignoring the knowing looks John was giving him. Just because he felt more alert and focused after eating didn't meant eating had anything to do with that.
It was undoubtedly the coffee.
They cabbed it up to the B&Q in Cricklewood and Sherlock glanced about with interest when they entered the store. There seemed to be all manner of interesting materials here, and he wondered why he'd never bothered to investigate this kind of place before. Who knew what could be found to be used in experiments? Perhaps he should take some notes? He sniffed the air carefully – it smelled of pine and concrete and various plastics and oils and paint.
"You look as though you've stepped into a whole new world," John commented.
"Fascinating place," Sherlock replied. "What do you suppose the logic is behind the layout? Where does one begin to look for painting supplies?"
John stopped, giving him a disbelieving look.
"You mean to tell me you've never been in a hardware store before?" he demanded.
"No," Sherlock said. "Why would I have been?"
John stared at him.
"But where –" he stopped himself, then sighed. "Well, I suppose you never do any repairs around the flat. And you had people who did that sort of thing for you when you were growing up."
"I didn't have people, John," Sherlock said, feeling slightly like he needed to clarify this. "My parents had people. It's entirely different. I wasn't paying them, so they could not, by definition, have been my people."
"Uh-huh," John said, giving him a very John look, tinged with amusement. "If you say so, Sherlock."
"I did want to paint my bedroom once, when I was four," Sherlock offered. "I was not permitted to."
"Probably a wise choice," John said.
"I think I could have done a rather good job," Sherlock sniffed. "Had they only provided me with a ladder. I didn't quite have the height then that I do now."
For some reason, John rolled his eyes at this.
"Look," he said, pointing. "I think the sign that says 'paint' may be a clue as to where we can go. But how do you know we'll find her in the paint section?"
"She's an artist, although she was working with pencils and charcoals, but she had paint stains under her fingernails, where it's hard to get off, and her hands were dry, from cleaning them, probably with varnish."
"We don't even know if she's here," John pointed out.
"No, but if she's not, we can get her home information from her managers."
"And why would they give that information to you?"
"Because I have a police badge."
John stopped again, staring up at Sherlock.
"You– wait– what?" he demanded, somewhat incoherently.
"Nicked it off Lestrade this morning. Don't worry, John, I fully intend to return it. Once I'm finished with it."
"Oh, I don't bloody believe this," John muttered, but completely negated his words by falling into step beside Sherlock, who smiled inwardly at this. Always so rewarding when John caved, although he did enjoy timing the doctor to see how long it would take. Since Sherlock had actually consented to eat something, John was going to be more willing to go along with whatever the detective wanted.
It was such an interesting give-and-take, with John.
"Here we go," John said, pointing up the aisle and Sherlock frowned.
"Where?" he asked.
"That sort of booth in the centre up there," John said. "That's the paint mixing station."
"How do you know that?" Sherlock demanded.
"I've bought my fair share of paint, Sherlock," John said, rolling his eyes. "Used to help my dad paint the house when it needed it, and I've painted a flat or two in my time, when I was a med student."
"Could you paint our flat?" Sherlock asked curiously.
"Um, only if we wanted Mrs. Hudson to evict us," John said. "And it's a bitch to paint over wallpaper, we'd have to take it all down to do it properly. Which is also hard."
Sherlock frowned slightly; he didn't like the idea of that. Besides, he did like their flat precisely the way it was, because it was home. He couldn't imagine Mrs. Hudson actually evicting them, because who would she get to replace them? No one nearly as interesting. But best if she didn't even threaten, he supposed.
"Ah," Sherlock said, smiling then. "There she is."
A young woman had just appeared, standing up from behind the rectangle of counter that was oddly situated, in Sherlock's mind, in the centre of the aisle. They passed by various types and brands of paint and he wondered what the differences were, although yes, clearly, outdoor paint would be different than indoor paint, given the effects of weather on chemicals.
She glanced up at them as they came up the aisle; the store was not particularly busy at that time of day. Her smile was bland for a moment, with no recognition, then she looked slightly surprised.
"Oh, I remember you," she said as Sherlock and John stopped on the other side of the counter from her. "From Angelo's, last week, right?"
"Quite right. Sherlock Holmes. John Watson," he added, gesturing to John.
She grinned, brown eyes bright. Her dyed red hair was still pulled back from her face, but with more deliberation this time, into a braid that let only some strands loose about her face. Sherlock put her at about nineteen or twenty, which suddenly struck him as very young.
"Well, Holly Adams," she replied, even though Angelo had told them her name, remembering her last name after a bit of thought, and she was wearing a name tag that gave her first name and last initial. "What can I do for you? Do you need some paint?"
Sherlock shook his head, pulling out Lestrade's appropriated police badge and flashing it. Her smile froze, then faltered before vanishing quickly and she looked between the two of them, eyes widening.
"Has something happened?" she asked quickly.
Sherlock hated that question. It was ridiculous. Of course things were happening – things were always happening. They didn't stop happening to accommodate others, although the possibility of this being the case struck him as convenient when he needed it. Unfortunately, these rules seemed to apply to him as well.
"No," John cut in quickly, giving Sherlock a glare that seemed unnecessary. "Not to anyone you know, at least. We've actually come for your help on a case."
Sherlock huffed silently at John's interruption but the girl's expression cleared after a moment's hesitation. She looked at John, then back at Sherlock, uncertain now. Had she misunderstood what John had said? He'd been fairly clear.
"Sorry, my help on a case? What kind of help? What kind of case? Why would the police want me?"
"It's a murder investigation," Sherlock said shortly. "You have a talent for colour, yes? I saw your drawing of the cellist last week, it was superb. And you work with paint mixing, so you must have a good grasp of shading and its subtleties."
"Tinting," the girl said, almost automatically, then blinked, as though surprised she'd corrected him.
"Sorry?" Sherlock asked.
She sighed, giving him a bit of a rueful smile.
"It's tinting. Shading is adding black to a colour. Tinting is adding white. That's what we do here. All the paints are white as a base."
John gave Sherlock one of those irritating grins that revelled in the fact that Sherlock had been upstaged by someone, and Sherlock was not at all pleased that this was the second time in one day this had happened. But he ignored it in favour of knowing he had been right about the girl, Holly, and her abilities. Anyone who would correct that kind of detail would be well suited for what he needed her to do.
"Tinting, then," he agreed.
"Does the killer use paint?" the girl enquired.
"No, coloured scarves to bind his victims," Sherlock replied.
At this, she looked alarmed again and Sherlock didn't understand. It wasn't as though the killer was there with them, or there were dead bodies lying about the store. Although that would be interesting, wouldn't it? And perhaps the killer had followed them? He entertained that idea, knowing it was so unlikely as to be preposterous, then reminded himself to berate John later for making him eat and forcing his mind to be distracted as he digested.
"You wouldn't have to see any crime scenes or corpses," John was saying and Holly was looking at him again, with a mixture of confusion and relief. "But photographs of the victims, although they are not very graphic, believe me. What we really need is someone who can distinguish between the shades of blue in the scarves."
"Why?" Holly asked.
"There's a message in the pattern," Sherlock replied. "But I can't distinguish between all of the shades, and without being able to do so, I cannot accurately interpret the message."
She stared at him, as though he was slightly mad.
"Why would someone do that?" she asked.
Ah, Sherlock thought. Well, it wasn't him who was the mad one then, but it bore explaining.
"He's a serial killer," he said. "A psychopath. And he's killed ten people. Your help could prove invaluable."
"What?" she demanded, but probably not in response to the last statement, then shook her head. "Are you – you're serious about this, aren't you? It's not going to get me killed, is it?"
Sherlock evaluated the odds.
"Unlikely," he said. "Although I can't account for contingencies such as traffic accidents, of course."
"What?" she asked again, looking at John for clarification. John waved a hand.
"Don't listen to him," John sighed and Sherlock scowled, but the girl's expression seemed a bit clearer. Did she find John more trustworthy? If so, why? "He likes to make sure he's covered all of his bases, but no, you aren't in any danger, even if you help us. Helping us would actually help catch him, and get him put away for quite a long time."
"Life, actually, given the number of people he's killed," Sherlock clarified.
She looked between the two of them again.
"And you need me? You don't have police officers who can do this?"
There probably were, Sherlock knew, but he wasn't about to chase them down when he could access an expert such as her quite easily. And this way, he would owe no favours to anyone on the police force. He much preferred they owed him favours, which they would, if he solved this. With Holly Adams' help. Which Lestrade did not need to know about.
"You're much more qualified," he assured her.
She hesitated again, but Sherlock felt a stab of triumph knowing he'd won, because it wasn't the kind of hesitation that preceded someone refusing.
"What do I need to do?"
"Come with us and look at some evidence – the scarves themselves and some photographs. That's all."
"I'm on a shift right now," she pointed out, as though somehow, Sherlock may have missed that detail.
"We're police," he said, which was, not to put too fine a point on it, not true.
"But if I leave, I don't get paid. And no one else is here to do mixing right now."
Sherlock sighed – why were other people's schedules so troublesome? They had nothing to do with him, yet he was constantly affected by them. It was tedious.
"When do you finish your shift?" John asked.
"About two hours," the girl said.
"Right," Sherlock said, snagging a random business card from his wallet, someone he'd met that he had no intention of contacting anyway, and scribbled their address on it, then pulled out two twenty-pound notes from his wallet for good measure. He jotted his mobile number on the back of the card, too. "When you're finished, take a cab to this address, and ring me on your way over. I don't expect it will take too long, and I shall pay you, of course, for your time."
She held up the two twenties.
"And this is?"
"Cab fare."
"It can't cost that much."
Sherlock shrugged; people were always so fussed about money, which he also didn't understand.
"Use what you need," he said. "The rest will go toward your fee."
She blinked, then nodded, almost automatically.
"Two hours then," Sherlock said, as though to remind her. Holly was looking at the business card, appearing somewhat confused, as if she was surprised she'd agreed to this.
"Okay," she said, and Sherlock smiled encouragingly at her, because people seemed to respond well to this, then grabbed John's arm, towing the doctor away before he could muck things up for them, or before the girl could change her mind.
John had insisted that Sherlock have Mrs. Hudson with them when Holly arrived at their flat, so, as he put it, "she wouldn't be scared off". Sherlock thought this typical of John, who had unnecessarily odd ideas about how people behaved, but he'd acquiesced, just in case John was right. It would not do to have his expert leaving before she'd accomplished anything, because then he would have to find someone in the police force who could do this sort of thing.
John even made him wait upstairs when the girl arrived. Sherlock listened with half an ear to the conversation below, noting that Holly at least did not seem too put off about turning up at a private residence instead of a police station, although she did enquire about it. John and Mrs. Hudson both reassured her that police investigations sometimes worked this way, although this was not precisely true. But both of them, especially John, could be quite reassuring, when they had a mind to be.
She came upstairs with John and Sherlock gave her a welcoming smile, because she was clearly uncertain about this whole thing. Holly looked about the flat, but did not seem particularly shocked and he knew he'd judged well. As an artist, she was probably used to some disarray in her possessions, particularly her workspace, although he refrained from saying so to John, who liked to accuse him of pandering to stereotypes.
"Thank you for coming," Sherlock said, standing from his chair at the table. She nodded, giving him a quick but not entirely confident smile, looking around again, as though there may be a corpse hidden underneath the mess of files that littered every available surface, and some unavailable ones as well.
She was still in her work clothing, even still wearing her work smock, with paint on her hands from her daily tasks, and a small smear on her cheek, which she did not seem to have noticed. She cast another glance about the flat, this one more evaluating, judging the light, he thought. She was carrying a canvas bag decorated with designs in permanent marker, probably her own work.
"What do you need me to do?"
"Put these on," Sherlock said, handing her a pair of latex gloves. She took them and snapped them on, running her index fingers under the cuffs against her wrists, trying to straighten them, obviously not used to wearing them.
"I need you to look at five set of scarves and match the shades up with the pattern in some pictures," he said. "There are several shades of blue, but I cannot accurately gauge how many. I need an exact count, and I need to know how many scarves are the same shade, and how many are unique shades."
She bit her lower lip nervously.
"What are the pictures going to show?" she asked.
"The victims tied with the scarves," Sherlock said bluntly. "They were all shot, but they were cleaned before they were bound, so you won't see anything untoward in any of the pictures, but there is dried blood on some of the scarves. I've folded them so it shouldn't be visible, however."
At this, John looked surprised, even though he'd watched Sherlock folding the scarves and hadn't asked why, so Sherlock had assumed John had deduced his actions. Holly looked surprised, but for a different reason.
"Well I can deal with blood," she said. "I just don't want to see guts spilling out all over the place."
Sherlock's lips twitched in a smile.
"The photographs are fairly clean, I assure you."
"And that's all you want me to do? Just figure out the shades? That will help you break whatever mad code this lunatic is using?"
Sherlock cocked an eyebrow.
"Presumably," he said.
"Well, um, okay, I'll give it a go," she replied. He gestured her over to the table.
"There are five scenes," he said, pointing them out. "The first and last scarf you can ignore, because they're different colours. Keep the scarves from each scene separate – if they become mixed up, it will be difficult for me to sort out the meaning after you've accounted for all the shades. Best just to keep everything in order. None of the police officers who recorded the scenes noted the differences in shade, so I'm uncertain if the order in which I've laid out the scarves is accurate. I need you to determine that first, then how many shades and how many of each shade."
She looked down at the table, eyes skittering over the scarves and photographs.
"Can I tag them?" she asked.
Sherlock blinked.
"Yes, of course," he said. "Number the scarves one through seventeen. Do you know Roman numerals?"
"Ah, a bit," she said. "You want me to number them that way?"
"No, I want you to number them using Arabic numerals, but designate the shades using Roman numerals."
"Why don't I just use regular numbers and then letters for the shades?"
"Because if the shades represent letters, it will become confusing. If you need help, I can provide it."
"Um, okay," she said. "I think I can manage."
"Good," Sherlock said, probably more confident in her abilities than she was. "John, can you please get some twist-ties from the kitchen?"
As John did this, Sherlock fished out several evidence bags, then set work securing each of them to the ties John had fetched from the kitchen. He put them on the table for her and gave her a permanent marker, then pulled out a chair, settling himself onto it.
"Are you just going to sit there and watch me work?" she asked, looking startled.
"Yes," he said. "I want to see what you do. You were working fine in Angelo's while others were watching last week."
"Yes, but, that was– normal," she managed. "This is not. I mean, I've never had to help solve some kind of criminal case before."
Sherlock just shrugged, unconcerned. She cast a look at John, and Sherlock knew his husband was probably wearing an apologetic expression, but indicating silently that he could do nothing about it.
"Well, okay, but what if I'm wrong?" she asked.
"I want you simply to try," Sherlock replied. "If I can't decipher the message based on your judgement, I'll try other avenues to solve it."
She stared at him, trying to determine if he were serious, then sighed and bent over the scarves, brushing her hair behind her ears, even though it was still in its braid. Sherlock watched carefully and curiously; she was quite tense, and was avoiding picking up any of the photographs, even though she examined them studiously, bending over the table to narrow her eyes at the colours of the scarves.
Hesitantly at first, she shifted the scarves from the first murder around, then shook her head, sucking in a deep breath. For a moment, her eyes flashed to him, but he just nodded, gesturing for her to continue. She moved to the second case and then frowned, shaking her head, shifting the third and fourth scarf positions, and Sherlock saw her confidence return suddenly.
"Can I have a sheet of paper?" she asked and he provided her with one. She began making quick marks, eyes darting over the scarves, over the photos. Holly rearranged most of the scarves from the third murder, save for the fourth one, then nodded at the arrangement he'd made for the fourth case. She glanced back and forth between the fifth case, the fourth, and the second, and make some quick marks on her paper, eyes darting over the photos again, over the scarves.
Then she pulled back, pursing her lips, counting silently by tapping her left index finger in the air. Sherlock heard John shift behind him – he'd taken up his perch on his chair and was staying silent, but seemed about to ask a question. Not wanting to interrupt the girl, Sherlock held up a hand and John stilled again.
Holly nodded to herself, dark eyes flashing, then began to label the bags Sherlock had provided for her, twisting one onto each of the seventeen scarves.
"You have ten different shades of blue," she said, finally, after about twenty-five minutes of concentration, writing, and labelling. "Look here. Four of them repeat. This one," she pointed to one that Sherlock had suspected was the most common, "repeats four times. This one and this one each repeat twice. And this one repeats three times. That leaves you with six that don't repeat at all."
He nodded and she jotted this down on the paper for him.
"This one is your lightest shade," she said, pointing to the last scarf from the first murder. "And this one is your darkest." This was the second scarf from the second murder. "This one, the one that repeats four times, is the one right in the middle. You have a lot that are close to one another, but your lightest and darkest are quite distinct. The ones in the middle are closer to one another."
"But you're sure they're different?" Sherlock asked, because he was not certain he could see a distinction.
"Yes, definitely," Holly replied. "This one, that only appears once, it's just a hair darker than the one that appears four times. And these two," the fourth scarf from the second murder and the first scarf from the third, "they're a shade off from each other, too, at least in this spectrum he's using, but darker than the most common one. What do you think this is? The alphabet? Numbers?"
"I'm not certain yet," Sherlock said. "Anything else you can tell me about them?"
She looked at the sheet on which she'd jotted all of her information, then shook her head.
"No," she admitted. "That's it."
"Brilliant," Sherlock assured her, giving her another smile. "Very well done."
"I hope it helps," she said.
"If it doesn't, I'd be surprised. One moment." He fished his wallet from his coat pocket and opened it, pulling out four fifty pound notes and passing them off to her.
"I can't take that!" she exclaimed.
"A fairly standard payment for someone with your level of expertise," he told her.
"But I've barely done anything," she said. "It's taken me no time at all."
"Would it count as nothing if you helped apprehend a serial killer?" he asked. "Please, take it, but it's also imperative you do not mention this case. It's an ongoing investigation, so any discussion could jeopardize the results."
She glanced up at him, trying to evaluate if he was serious, and Sherlock put on his best responsible policeman face. This was actually true, but he also didn't want Lestrade to get wind of her involvement.
She hesitated again, but when he didn't withdraw the money, she accepted it.
"All right," she agree. "Anything else?"
"No, thank you. John will see you downstairs and ensure you get a cab. Thank you for your assistance."
She nodded, pulling off the gloves and Sherlock took them, heading into the kitchen to bin them. John took the girl down to the street and came back a few minutes later, to find Sherlock in front of the mirror, having marked seventeen underscores on the glass, followed by a question mark. He ignored the groan John gave at the sight of the mirror, because they'd obviously have to buy a new one, and met the doctor's reflected eyes.
"We know how he was trying to send the message," Sherlock said, nodding at the reflection of the table behind them. "Now we just have to determine what it is he's trying to say."