He'd been thinking about the loop.
Not the mechanics of it — he understood the mechanics, or thought he had. What he'd been thinking about was something underneath the mechanics, a question that had been sitting at the edge of his attention since Day 32 when Maya's first proper cultivation session had run and he'd felt the energy passing through the connection with a cleanliness and structure it hadn't had before.
The question was simple. How.
His status panel said Cultivation: None. It had said that every time he'd checked it since sprouting. No cultivation. No heartwood. No refinement core. And yet the loop had been running — Maya absorbing raw energy, something refining it into wood element energy, refined energy returning to her. That refinement had to happen somewhere. The Heartwood connection was a channel, not a processor. Channels moved things. They didn't transform them.
Something was doing the transformation. Something that his status panel wasn't acknowledging.
He went to his question tab.
The Heartwood connection has been returning refined wood element energy to the connected practitioner since Day 32. My status shows no cultivation and no heartwood. What is performing the refinement?
The system's response arrived with the particular thoroughness it brought to questions that touched on something significant.
At the initiation of the assisted cultivation session on Day 24, the system's one-time cultivation assistance created the minimum biological infrastructure required for the Heartwood connection to function as a refinement loop. This infrastructure — referred to as proto-heartwood — is a rudimentary precursor to the full heartwood structure. It is insufficient to register as active cultivation on the host's status panel and insufficient for meaningful qi accumulation. It is sufficient to perform basic refinement of neutral spiritual energy into wood element energy for return to connected practitioners.
Proto-heartwood will be absorbed into and superseded by full heartwood formation at sapling threshold. Refinement quality and retention capacity will increase significantly at that point.
He read it twice.
Then he sat with it for a while.
The assisted cultivation session. He'd given it to Maya as a quest reward — the system's one-time offer transferred to her through the Heartwood feature. He'd assumed it had done for her what it would have done for him: walked her body through the cultivation process once, given her a reference point, started her dantian accumulation. He hadn't known it had done something for him simultaneously. The system spending a portion of that one-time assistance on creating the minimum infrastructure needed to serve her — a proto-heartwood, barely there, not enough to count, but enough to function.
He thought about that for a moment. The system had used the assisted cultivation to help both of them at once. He hadn't directed that. It had simply done what was most efficient given the circumstances.
He filed that as something worth remembering about how the system operated and moved on.
What is the proto-heartwood doing between Maya's active sessions?
Between active cultivation sessions the proto-heartwood continues passive biological refinement at a reduced rate. Neutral spiritual energy generated through the host vessel's biological processes is partially refined through the proto-heartwood and emitted into the immediate environment as wood element spiritual energy. The remainder is emitted as neutral spiritual energy. Neither portion is retained for the host vessel's accumulation at the proto-heartwood stage.
He had a follow-up question forming before he'd finished reading that.
The host vessel's biological processes generate spiritual energy. Explain the mechanism.
The system's explanation was the longest response he'd received from the question tab since asking about cultivation fundamentals in the underground weeks.
He read it carefully, the way he read things he was going to need to understand completely rather than approximately.
All trees — cultivating or not, conscious or not — generated a small amount of neutral spiritual energy as a biological byproduct of photosynthesis. The mechanism was specific: sunlight carried trace amounts of primordial energy alongside its ordinary electromagnetic spectrum. This primordial component was the same energy that ancient practitioners had drawn from high-altitude practices, from extended sun exposure, from sitting in old-growth forests — a real and present component of sunlight that ordinary organisms couldn't access or process.
Trees were different. The unique geometry of their vascular systems — the arrangement of xylem and phloem that moved water and nutrients from roots to leaves and back — created a biological structure that inadvertently captured this primordial component during photosynthesis alongside the ordinary light spectrum. The tree's chlorophyll processed the ordinary electromagnetic energy. The vascular geometry captured the primordial trace and converted it, through the same biological processes, into neutral spiritual energy as a byproduct.
Net new spiritual energy entered the world through this mechanism. Not conservation of existing energy — genuine generation. Every tree was a small spiritual energy source. Ancient forests containing millions of trees had been generating spiritual energy continuously for centuries, accumulating it in the soil and air and water of those environments, which was why ancient cultivation sites had been located in old-growth forests and sacred groves. The practitioners who designated those places had understood intuitively what the mechanism explained precisely.
Modern deforestation had eliminated the generation source. The spiritual energy density of the modern world wasn't just low because cultivation had stopped — it was low because the trees that had been generating it for millennia had been cleared.
He thought about the apartment. One mango tree on a windowsill. The contribution to the world's spiritual energy density was essentially unmeasurable at this scale. But the mechanism was real and the direction was right.
How does the generated spiritual energy leave the host vessel's body?
Neutral spiritual energy generated through photosynthesis travels through the host vessel's vascular system — the same pathways that move water and nutrients — and is emitted continuously from leaf surfaces and root tips into the immediate environment. This emission is passive and biological, requiring no conscious direction. It occurs in any tree regardless of cultivation status or consciousness. A cultivating tree emits more than a non-cultivating tree of equivalent size due to cultivation enhancing the efficiency of the biological processes that drive generation.
At the proto-heartwood stage, a small portion of this emission is partially refined to wood element energy before emission. At full heartwood formation, refinement capacity increases significantly and a portion of generated energy is retained for accumulation rather than fully emitted.
He thought about Maya's morning practice sessions before the Evergreen Method had arrived. She'd been sitting near him on a cushion in the early morning kitchen, cross-legged, eyes closed, trying to find the sensation the assisted session had shown her body once. He'd felt her presence in the dome — the quality of focused stillness he'd come to associate with her practice sessions. He'd known the proto-heartwood was doing something during those sessions even without understanding the mechanism. Now he did.
She'd been absorbing his passive emission. Not the refined loop — the crude continuous output of a seedling's vascular system emitting neutral and partially refined wood element spiritual energy into the three feet of air around him. Small amounts. Barely above the modern ambient baseline. But present, and cleaner than the ambient, and enough for a body that had been shown once what cultivation felt like to begin finding the sensation again.
He thought about the assisted session and what the system had actually given both of them that day.
He thought it had been rather more efficient than he'd understood at the time.
At sapling threshold, what changes in the refinement process?
Full heartwood formation replaces and supersedes proto-heartwood. Refinement capacity increases substantially — refined elemental energy output quality improves, retention of a meaningful share for host vessel accumulation becomes possible for the first time, and the refinement loop with connected practitioners operates at significantly higher efficiency. The host vessel's status will update to Cultivation: Active upon full heartwood formation.
He checked his own status one more time.
[ STATUS ]
Vessel: Mangifera indica (Mango Tree)
Stage: Seedling — Late development
Permission Level: 1
Cultivation: None
Immortal Arts: None
Techniques: None
Heartwood: Active — 1 connection
Still none. Still late development. The height marker was the last remaining threshold — two centimeters, four days at current growth rate, maybe less if the loop continued improving.
He thought about what the system had just told him. The proto-heartwood had been doing its small quiet work since Day 24 without appearing on his status panel, without his full understanding of what it was, returning refined wood element energy to Maya through the loop while retaining nothing for himself. All of it dispersing. All of it serving the connection rather than his own accumulation.
That would change at sapling threshold. The full heartwood would form and the retained share would finally mean something — actual accumulation, actual progression, the status panel updating for the first time since the very beginning.
Four days.
He returned his attention to the leaf surfaces where the vascular emission was happening continuously and silently, the way it had been happening since the first shoot broke through the soil, and thought about primordial energy and ancient forests and one mango tree on a windowsill in a modern city doing its small part to put something back into a world that had been losing it for a long time.
He found that he didn't mind being small at this particular moment in the story.
Small things could become large ones. He had time.