Two Years [Early Morning / Laboratory]

Taekyung entered the empty lab alone.

He reopened HN-365’s entire culture record.

Day 30.

Day 90.

Day 180.

Day 365.

The organoid had unquestionably grown.

But it was still far too young.

Taekyung typed into a note.

‘Hajun: age 3.’

Below it:

‘HN-365: 1 year in culture.’

Then one more line.

‘Expected survival limit: age 5.’

He stared at the three lines for a long time.

By the time Hajun turned five,

if the organoid continued developing at a normal pace, it would likely have reached only the equivalent of roughly three years.

It would still be two years behind.

And that was not the only problem.

Even if he could make it grow faster, there was no guarantee it would develop normally.

Its neural circuits had to form correctly.

The necessary cell types had to appear in the right proportions.

To survive transplantation, blood vessels would have to connect rapidly.

And most importantly,

it had to exchange actual signals with Hajun’s existing brain.

Taekyung dragged a hand over his face.

There was too much to do.

And too little time.

[Morning / Conference Room]

Taekyung conducted the research meeting as usual.

(Researcher) : “Should we include HN-365 in the next animal transplantation group?”

Taekyung answered immediately.

(Taekyung) : “No.”

(Researcher) : “It’s the sample you’ve followed the longest.”

(Taekyung) : “That’s exactly why.”

After the meeting, a junior researcher approached cautiously.

(Junior Researcher) : “Professor, you’ve been checking that sample constantly lately. Is something wrong?”

Taekyung paused.

(Taekyung) : “I’m reviewing the long-term culture data.”

It was a lie.

For the first time, he had hidden the real purpose of his work from his own lab.

[Night / Laboratory]

Taekyung entered the date beside the culture log.

The days remaining until Hajun’s fifth birthday.

D-728.

Seeing the number on screen made it hard to breathe.

What had to be done in 728 days.

Advance tissue at a one-year developmental level to the equivalent of age five.

Do it without disrupting the order of normal development.

Stabilize vascularization.

Confirm normal neural circuit function.

Verify survival after transplantation.

Confirm the possibility of functional integration with existing brain tissue.

Animal testing.

Surgical planning.

Taekyung stopped before he could finish the list.

It was too long.

And time only moved in one direction.

He looked again at HN-365.

(Taekyung, quietly) : “At the normal rate, it’s impossible.”

From that moment, the question changed.

It was no longer,

‘Is it possible?’

It became,

‘How do I shorten the time?’