As usual Lan WangJi awoke at 5:00 AM. As usual he meditated until he woke Wei WuXian at 7:00 AM with the usual difficulty, or perhaps slightly more. As usual, breakfast in the Jingshi, then separating to their individual duties. Unusually, for men facing the collapse of their known world, the routine did not reassure.

Wei WuXian took the dozen steps commute to his workroom, lost in thought before the final step. Seated once more behind his desk he reviewed his findings of the day prior. Interesting, but nothing particularly helpful. What to try next? Brows drew together above a slight frown as he considered how to further investigate the pellets. Well, if visual inspection yielded little by way of results, perhaps a more physical inspection might help.

On the workbench Wei WuXian set out four small bowls. In them he placed four different liquids – water, vinegar, alcohol, oil. Into each bowl he carefully placed a single pellet in turn, paying strict attention to each and observing for a considerable time before moving on to the next. One by one he made his observations and recorded the results. And one by one he was dismayed to find no result whatsoever, with a single minor variation. No change. No loss of structural integrity of any pellet, excepting perhaps a very slight softening of the pellet that had rested in vinegar. No change in the colour or odour or consistency of any of the four liquids. He drew out the pellets and placed them back in their individual little dishes to dry and shed the remaining liquid from their surface. And one by one each pellet was restored to its original pristine appearance. No change in the surface sheen or texture. No apparent dissolving. Nothing.

The whole morning gone and still nothing helpful! Wei WuXian thought bitterly. This is already the second day from Healer Zhang's warning. How can I...oh gods! His thoughts were interrupted by another violent wave of pain, once more forcing him to the floor, reaching for a basin. He breathed through the agony as best he could, until it finally passed. I may have to visit the Healing Hall after all, he thought. I'm not sure what this is, but it can't be good! He lay on the floor and collected his thoughts. There was no reason for the pain or vomiting he could bring to mind. The pain wasn't in one place but more of an all-over, overwhelming sensation. How can I even explain something this vague to a Healer? he wondered. The low-grade constant pain is bad enough, but an attack like this in the middle of each day? On top of those hellish nightmares? I can't tell Lan Zhan how bad it is... he has enough to worry about. I won't add to that. I won't! Sheer determination to conceal the situation from his beloved drove Wei WuXian back to his feet and the task in hand. His dogged will carried him forward until his body and mind recuperated sufficiently to return to his work.

Wei WuXian decided not to risk the mid-day meal on his suffering stomach. The morning light had passed, so he brightened the workroom to continue. He had been looking directly at one of the pellets when he brought the lights up, and something about the finish in the brightness caught his attention. Picking up the pellet in question, number 6, he brought a lantern close. Rotating the pellet and watching very closely, he noticed something subtle he'd failed to notice previously. Perhaps it had simply not been visible in the light at the time, but when he moved the pellet in his fingers there was subtle glimmer to the surface. He concentrated and used his will to force the wisps of resentful energy being released between his fingertips to drift away from him, leaving more of the surface visible. What could this be? Drawing fresh parchment, Wei WuXian began to inventory the pellets again. With a lamp close at hand, one by one he rotated each pellet, focussing intently on the finish and what he could see revealed by the brilliance being beamed directly onto the surface. One by one he noticed something in common.

Every single pellet had this specific glimmer. Not precisely a metallic finish. Nothing like the mica flecks sometimes used to adorn jewellery or decorative objects. No, this was much finer. Much more subtle... what it looked like more than anything was metal. But not in a form he'd ever used or heard a use for. It had to be powdered. Ultra-fine flakes of metal, ground to particles no larger than dust motes.

Wei WuXian finished his inspection and sat back, stroking his nose. Why would anyone put powdered metal into a pellet? What would the purpose be? Metal is a solid, would it not pass right through the human body's digestive system? Coming to no conclusions on his own, Wei WuXian decided to check with those who should know. With well over an hour before the evening meal, he took himself off to the Healing Hall.

Arriving at the Healing Hall, Wei WuXian asked if a Healer was free to speak with him. He waited patiently – by his standards, only tapping his toes and pacing a little – until a Healer was summoned.

"Healer Shui!" Wei WuXian was surprised when a Healer he knew turned up. He hadn't been at Cloud Recesses long enough to be familiar with many of their Healers, but he remembered the Healer who had given him the glad news about his Core finally developing.

"Master Wei," the Healer bowed in greeting. "How are you today? I hope you are not having any more problems?" He ran his eyes over his caller, noting the increased pallor and dark circles.

Wei WuXian's ready smile faltered only a moment before he determinedly brought up the reason for his visit. "Oh, no change, no change," he dismissed his health without a second thought. "I have a question that I thought a Healer would probably be the best to ask."

"If I can help, please ask," welcomed Healer Shui.

"What happens when a person consumes metal?"

Healer Shui looked puzzled. "Do you mean eats metal deliberately? There is a very rare condition where people feel compelled to consume non-food items, and that can include metal objects. Metal can also be used to poison someone – mercury is often a means of assassination – but it's usually ingested without awareness."

"No, I mean if someone took metal, ground it very finely into a powder, then fed it to someone. Mixed it into something else, perhaps disguised it as a medicine?"

The Healer made a face. "That would be difficult to manage. Metals have a very distinctive tang and few people would remain unaware of it if it were mixed into their food."

"What if it were taken in a way that taste was not an issue? Say a very small quantity? Perhaps added to a medicine, such as a pill that could be swallowed whole, without tasting? What would happen to the powder as it passed through the body?"

"The body is made to eliminate non-food items," began the Healer. "If metal were consumed, it should pass through the body until it is eliminated as a solid. If the metal were powdered finely enough it is possible that some particles could become lodged within the person's tissues and remain within their body, but it would have to be a very fine powder. Does that help at all?"

"Thank you, Healer Shui. Yes, it does tell me what I needed to know. Oh, one more question?"

"Yes?"

"The human body. When it consumes food. The stomach fluids are a kind of acid?"

"Yes. Bile is very corrosive and essential for breaking down what we consume. Are you perhaps having some stomach troubles?"

"Oh, no, no. Just researching, that's all, thank you. I did have one personal questions, if I may ask?"

"Yes?"

"Why would my Core be developing so quickly now? I've had it for some time and while I've worked on it all along, it's only recently shown any signs of developing. Why would that be?"

Healer Shui dropped his eyes a moment, then looked again at Wei WuXian. "What do you understand about Dual Cultivation?" he asked.

Wei WuXian blinked. "Umm, not a lot? It was mentioned, but never really talked about. When I was young, our questions were dismissed, and we were told when we married, then we'd find out..." his voice trailed off as the penny finally dropped. "Married. Dual Cultivation. Dual Cultivation. Oh. So, Lan Zhan and I..."

Healer Shui nodded. "Yes. A couple that enjoys a positive, healthy connection will boost each other's Cultivation through their shared intimacies. It takes true and selfless devotion to experience this specific benefit of marital relations, as energy is gifted to the partner. In rarer circumstances, it can be further progressed by the deliberate and overt choice to mutually share spiritual energy during the act itself."

Wei WuXian blushed. He couldn't help it. This wasn't a conversation he'd expected today nor one he'd ever expected to have at all. He opened his mouth to reply, paused and closed it. He tried a second time and again failed to say a word. Giving up, he bowed his thanks and turned to leave.

"Wei WuXian?"

'Yes?" Wei WuXian's voice squeaked as he replied.

"You will remember to tell me if there is any change in your health, will you?"

"Yes, Healer Shui. I will." Wei WuXian quickly made his exit, thoughts milling about how to move forward with the investigation and utterly distracted by the concept of Dual Cultivation. By the time he returned to the Jingshi there was still a bit less than an hour before the evening meal. He had a plan to move forward to investigate the pellets and a firm resolve not to even think about Dual Cultivation until this evening with Lan WangJi.

In the workroom, Wei WuXian took a fresh basin from his workbench. He sat down and deliberately stuck the blunt end of his brush down his throat, triggering his gag reflex and forcing him to eject the limited contents of his empty stomach. Seeing the bile in the basin made him feel even more ill, but he quickly swallowed down the sensation. Using a spoon, he took some fresh bile and added it the tiny dish holding pellet 6. Nothing was immediately visible, so he took some time to tidy away his earlier experiments, organize his notes and clean the basin just used. He then returned to discover pellet 6 had entirely dissolved.

So, it is dissolved by acid, he thought. But is it really a metal powder? And why would anyone feed a metal powder to someone?

He carefully added fresh water to the dish and allowed it to settle. Spooning away as much liquid as possible, he added more water before allowing it to settle again. Over and over, he did this until the fluid was clear and there was a trace of silt at the bottom of the dish, gleaming dully through the water. Carefully he poured off as much of the water as he could, without losing any of the particulates on the bottom of the dish. He used the edge of his sleeve to wick away more of the remaining moisture. He had just finished when Lan WangJi came to the Jingshi to collect him for the evening meal.

At the evening meeting, Wei WuXian brought Lan XiChen and Lan WangJi up to date on his work. He described his observations and his suspicion that there was powdered metal in the pellets. He walked them through his experiments, glossing over obtaining the acid necessary for the final step.

"By tomorrow the moisture should have fully evaporated and I'll be able to see what we have to work with," Wei WuXian concluded.

"How very strange," remarked Lan XiChen. "Why would anyone feed metal to Uncle? What purpose would that serve?"

"I can't answer that," replied Wei WuXian. "Tomorrow I'll work on seeing exactly what it is, if it is indeed metal, and maybe what type of metal if I can. At least it's something we can investigate."

"I appreciate your efforts," said Lan XiChen. "If you suspect this is being used to somehow poison Uncle, please be very careful when you are working. If we don't know what it is supposed to do, we don't know what it may do to you, either."

Lan WangJi gave a sharp look at Wei WuXian, who held up his hands to fend off the daggers coming from his husband's eyes.

"I promise, I promise!"

"Wei Ying!"

"Aiya, Lan Zhan, I promised you already. I will be very careful. I won't do anything I know to be dangerous, alright?"

"Promises are for keeping."

"Lan Zhaaaan, enough already. I promised and I'll keep my promise." Wei WuXian turned back to Lan XiChen.

"If I find out anything of note, I'll let you know right away." He turned to Lan WangJi. "And yes, husband, I will also let you know right away, too."