The line ran diagonally through the upper left of the sky, from the tree canopy to the edge of the canvas. Under the loupe it was dark — not black, but an umber that had thickened with age, sitting in a shallow valley between two layers of paint.
Maren photographed it, measured it, and noted in her condition report: Dark linear feature, approx. 31cm, orientation NW-SE, not following craquelure pattern.
That was the problem. Cracks follow the paint's drying history — they respect the grain. This line didn't. It cut across two distinct drying zones as if it had been placed there.
"Age crack," said Thomas, who owned the painting and was paying for the restoration.
"Maybe," Maren said.
Under infrared, she found that the line had density. It wasn't a gap in the surface but a mark beneath it — something painted, then painted over, then resurfaced through centuries of the upper layer thinning. A pentimento: evidence that the artist had changed her mind.
Or not. A later hand could have added the line. A student, a dealer, an earlier restorer who thought the sky needed a branch and then someone else thought it didn't.
"Can you tell?" Thomas asked.
"The pigment analysis might."
It did and it didn't. The umber matched the palette — consistent with the period, consistent with the artist's known materials, consistent with half the painters working in the region between 1650 and 1680.
Maren sat with the painting for a long time. The line bothered her because she couldn't place it. If the artist had drawn a branch and then painted it out, the line was a revision — an act of composition. If time had simply worn through the sky, the line was a symptom. If someone else had added it, the line was an intrusion.
Three different histories. One mark.
Thomas wanted a clean sky. He'd bought the painting for the landscape — the broad, quiet field, the receding light, the simplicity that made visitors stop in the hallway. The line disrupted that. He didn't care what it was; he wanted it gone.
"If it's original," Maren said, "removing it removes the artist's work."
"The artist painted it out. She wanted it gone too."
"She wanted it under. That's different."
He didn't see the difference. Maren did, but she couldn't articulate why it mattered. The artist hadn't erased the line; she'd covered it. The coverage was a layer with its own intention — the choice to leave the mark in the structure while removing it from the surface. A sky that knew it had a branch in it, even if no one could see.
Three centuries later, the sky had thinned enough to confess.
Maren mixed a small batch of solvent. Not for the line — for the varnish around it, which had yellowed and was distorting the greens in the middle ground. Routine work. She swabbed a test patch in the lower right corner, where the stakes were lowest.
The varnish came away cleanly. Underneath, the greens were sharper than she'd expected — a cold, mineral green that the warm varnish had been translating into something gentler for decades. The painting without its varnish was a different painting. Not damaged, not revealed. Just younger in a way that felt wrong, like hearing someone's voice on an old recording and finding it higher than you remembered.
She put the swab down.
The varnish was yellowed. The varnish was also two hundred years of mediation between the paint and the room. Every person who had stood in the hallway and felt the quietness of the field had felt it through that varnish. The warm greens were the painting they knew.
She could clean it. The cleaned painting would be closer to what the artist made. It would also be further from what the painting had become.
She picked up the swab again, worked the corner, and stopped at the tree line.
The line in the sky waited.