Isaac woke up early the next morning to do 30 minutes of stretches and sword stances. Then he washed up and left his house with a large sack of food. Of course, the destination was his locker.
He threw his pills and 2 reward points into the hemp bag he was carrying and continued onwards to the Cultivation Pagoda. The pagoda was only a 2-minute walk from the lockers, so Isaac arrived in no time.
He arranged to rent a room for 2 weeks; the 4th and 5th floors were fully occupied so he could only take a room on the 3rd floor. It didn't matter too much, since there weren't any material benefits to being on the top floors – Isaac just liked the views. So while he was slightly disappointed, he didn't pay it any mind as he walked up the stairs to the 3rd storey.
He opened room 37 using the key he'd been given and walked inside. The interior was a complete replica of the room he'd had on the top floor; it seemed every room in the pagoda was decorated the same.
It was a small, single-room apartment. Opposite the door was the room's only window and there was a mattress laid below it. To Isaac's right was a couple of shelving units and a small fireplace for cooking, and there was nothing on his left. The walls were painted cream white with red skirting boards and red highlights where the wall met the ceiling. Other than that, the room was plain and empty.
Isaac stowed his food in the cupboards, then sat down on the mattress and poured out his bag of Basic Qi Pills. They rolled on the mattress like small white marbles, and Isaac had to stop some of them rolling away.
When he had them all pooled in front of him, he didn't waste time and picked one of them up. Then popped it into his mouth like a candy. He used his will to follow its journey down his oesophagus and waited until it reached his stomach. When he felt the pill begin to release Qi as it was digested, Isaac swiftly infiltrated 3 Qi strands with his will. Then he pulled them to his Qi Core and blended them with it.
He'd become much more proficient at this process, especially after the previous 2 weeks of secluded cultivation. He absorbed the strands of Qi very efficiently and quickly went back to take more of them.
As Isaac hungrily absorbed the pill's Qi, his cultivation steadily grew. He kept absorbing strands of Qi and strengthening the walls of his Qi Core. As it got stronger and stronger, his core could safely hold more Qi and it was approaching the landmark of 30% full.
The next day, Isaac surpassed 30%. The day after that, he was nearing 32%. On the 4th day of cultivation, Isaac hit the 33% boundary to middle stage. It was late afternoon and he was still finishing that day's pill when he realised that, no matter how much he cultivated, his Qi Core didn't seem to get any stronger.
Isaac had already strengthened his Qi Core to the maximum that thin, lower-stage Qi could achieve. He would need to use purer Qi if he wanted to continue improving his Qi Core. In other words, he would need to strengthen his Qi Core by using the sudden surge of Qi produced by reaching middle stage. That way, he could achieve a qualitative improvement.
However, it was late and a breakthrough would take a while. Plus, it would take his maximum concentration so it was best to attempt it after he was well-rested.
Thinking this, Isaac stood up and stretched himself out. It was just past 5 pm right now, so it was still too early to sleep and rest up for tomorrow. Instead, he chose to do the thing that relaxed him most: read.
Isaac made an impulsive choice. He left his room and locked the door behind him. He descended 3 flights of stairs at high speed and left the pagoda, walking into the sect's bustling streets.
He pushed through the crowds on the street and made his way towards a quieter area. The nearest library was in a much less busy part of the sect, and Isaac quickly arrived before its glass doors. Warm light emanated from inside like a lighthouse which welcomed weary sailors, and Isaac didn't hesitate to step towards that warmth. He opened the door and stepped inside.
He immediately went to check the section for fantasy books, looking for the book he'd read last time he visited the library. Unfortunately, it wasn't there. There were 3 libraries in the Rank 1 district and the one Isaac usually visited was nearly a 1 hour walk from the Cultivation Pagoda, so he chose to visit this nearby one instead. It seemed that this library didn't have Isaac's book or somebody had already taken it out, so Isaac had to find another one.
He had a short search, then picked up a book about a swordsman with a 'void' cultivation talent – a talent so rare that all techniques for cultivating it had been lost. Of course, no such thing as a void talent existed in the real world, but Isaac still enjoyed reading a few chapters of the main character's struggles to cultivate. He even found himself laughing a couple of times – a rather rare occurrence. The interactions between the swordsman and his master were just too hilarious.
Eventually, Isaac put the book down. He'd lost track of time and 2 hours had flown by. He needed to return to the Cultivation Pagoda if he wanted to eat dinner and get to bed early.
On the plus side, he was supremely relaxed after his reading session. Reading was like a heavy rain: it washed away Isaac's concerns, schemes and complicated thoughts, leaving his mind fresh and clear.
Isaac left the library in this peak state of mind. He did exactly as he had planned to, returning to his room in the pagoda and eating dinner before he went to bed early.
The next morning, he awoke in his dark, quiet room. However, even in the morning gloom, his eyes shone with confidence.
He washed his face with a bucket of water one of the pagoda employees had brought up, then he went back to the mattress and sat down. He closed his eyes and sank into a state of calm concentration. Then he maintained that for 30 minutes, making sure his mind was clear of any doubt or hesitation.
When he was absolutely sure he was ready, Isaac began. He focused on his will, mustering as much of it as possible and bringing it all to his Qi Core. His willpower enveloped his Qi Core, completely surrounding it. Then it passed through, entering the core from all directions.
Isaac's will slowly contracted around the liquid Qi which filled up a third of the core. Then, he began to compress the Qi, trying to make it denser and purer. The Qi resisted and pushed against his will, but Isaac's willpower was too strong. He forced the puddle of Qi to get smaller and smaller, denser and denser.
As he did so, the compressed Qi began to emit a cloud of steam. These were the impurities in Isaac's Qi which were being forced out by the compression. Isaac had to split his will into 2 parts; he used the first portion to continue compressing the liquid Qi, while the second part went to trap the steam. He couldn't let his Qi Core absorb these impurities, so he had to extract them using his will.
The cloud of steam continued to grow as Isaac compressed the liquid Qi. Soon he wouldn't be able to contain all of it. He needed to siphon some of it away before that happened.
Isaac couldn't split his will again: performing 2 tasks at once was his limit. He had to change the shape of the will containing the steam, forming a funnel shape which pointed upwards. The base of the funnel caught all the steam which was trying to rise, while the funnel's spout pointed through the top of Isaac's core. A steady stream of impurity steam moved through the funnel and up the spout. As it passed through the walls of Isaac's Qi Core, it automatically tried to bind to it, but Isaac used the funnel of will to block it and force it onwards.
This way, he managed to force a constant flow of steam out of his Qi Core and deal with the steam produced by compressing his liquid Qi.
He continued to maintain this state – he didn't know for how long. Gradually, the liquid Qi became more compact and the amount of steam being emitted began to decrease. Isaac could see something forming in the middle of his liquid Qi. It looked like several tiny blue crystals were being created at densest points of Qi. As the compression continued, the crystals didn't get any bigger, but they slowly became a deeper shade of blue and more of them were produced.
Then, the crystals began to become more solid. However, Isaac couldn't let that happen. The crystals were the purest, most compressed part of his Qi and he needed to absorb them into his Qi Core to strengthen it to middle stage. If they became completely solid, his Qi Core wouldn't be able to absorb them and the breakthrough would fail.
Isaac had already expelled the steam of impurities and the liquid Qi wasn't producing any more, so he was free to use the other portion of his will. He moved it towards the ball of compressed liquid Qi and inspected all the crystals. When he felt one was about to become solid, he quickly pulled it out of the liquid before that could happen.
The crystal was slightly soft and gel-like. Isaac spread it like a paste on the wall of his Qi Core and tried to absorb it. The paste seeped into the wall of his core, filling any gaps in its surface and strengthening it.
Isaac made sure the crystal had been fully absorbed. Then he moved his will away and watched for more crystals which were about to become too solid. When he saw one, he would whisk it away and spread it on a different part of his Qi Core.
After absorbing over 100 tiny crystals, the pool of liquid Qi was almost completely gone. In fact, there was only a single drop left. Eventually, even that last droplet condensed into a crystal, which Isaac dutifully spread on the wall of his core.
There was no loud bang or flashy special event, just an empty Qi Core with much stronger walls. Isaac's breakthrough to middle stage was complete.