Sera had been assigned to the last lighthouse because she refused to get rid of her eraser.
More precisely, she had refused to erase the lines she was told to erase. A senior cartographer at the Chart Office had found seven red dots on her chart. All were rocks sighted outside the official shipping lanes.
“Unconfirmed observations do not belong on a chart.”
“That’s why I marked them in red.”
“Does being wrong in red make you less wrong?”
An answer might have cost Sera the posting entirely. She kept quiet and received the cheapest place on a boat to Roan.
Outside the cabin, beside a coil of rope.
“If you’re going to be sick, use the left side,” said Captain Nume. “The wind brings it back on the right. Very considerate.”
Sera gave up on the dry bread in her pocket. Every time the boat climbed a wave, her stomach climbed with it. She had drawn countless charts of the sea. The waves on paper had never moved like this.
“See the lighthouse yet?” Nume asked.
“No.”
“Hold off being sick, then. You don’t want to miss the first look.”
Sera gripped the wet rail and stood.
The fog parted.
A line of light reached down from a cliff. It wasn’t especially bright in daylight, but the sea beneath it lay flatter than the water on either side. Waves bent away at an angle, as if an invisible road had been laid across the surface.
When the boat entered that road, its pitching eased.
Sera’s mouth fell open.
On her charts, a shipping lane had been two lines.
Here it held the water in place.
“Last lighthouse still working.” Nume hauled on a sail rope. “The others shut down, or their stones went dark, or their people left. This one still puts supper on the table.”
A small pier appeared below the cliff. At its far end, a white-winged creature basked in the sun. Sera took it for a bird until she noticed the short flippers beneath its wings.
As the boat approached, it folded those wings and slipped into the water. Only its flat, shell-like back remained above the surface.
“Saltwing,” Nume said. “Don’t feed it because it’s cute. They chew through rope.”
“Animals eat rope too?”
“They like the salt on it. My work’s the saltiest thing on the pier.”
A boy waited there, waving the hand that held his hammer. His face fell at the sight of Sera’s chest.
“Books?”
“Paper and rulers.”
“Oh. Heavier.”
His name was Tio. He was an apprentice carpenter and helped the lighthouse keeper. Asked whether he liked the sea, he said he did when looking at it from land.
Nume unloaded Sera’s chest.
“I leave again before sunset. If you’ve forgotten anything, say so now.”
“Nothing.”
Sera looked back at the boat. The only boat going to the harbor. At Roan, she wouldn’t be able to pop out for something she needed.
The cliff stairs were longer than she expected. She took her first rest on step twenty-nine. Tio advised her not to bother counting to forty. There were more around the next bend.
A long-horned goat stood inside the lighthouse door.
It tried to eat her chart.
“No.” Sera held the paper above her head. “I haven’t even brought enough food for myself.”
A low laugh came from farther in.
“First cartographer I’ve met who explains her circumstances to a goat.”
Varen rose from a chair by the window and took up his walking stick. His right leg moved stiffly, slowly. His eyes, however, passed quickly over the assignment papers she offered.
“Recorder of errors?”
“Apprentice cartographer.”
“I heard they sent you here for leaving errors in.”
Her ears grew hot. That sentence couldn’t be in her papers.
Varen put a folded letter on the table: the Chart Office’s advance handover. She disliked knowing her reputation had traveled faster than her boat.
“I can work.”
“Say that after you’ve eaten. People fresh off a boat think they can do anything. Even get on another boat.”
He pointed to a small room beside the stairs.
One bed, one window, a desk fixed to the floor. Sera set down the chest and opened the window. The pier was very far below. Nothing stood between sea and sky.
She felt she had fallen onto the very edge of one of her own maps.
Inside her chest, a small flowerpot lay at an angle. Windgrass, a gift from her old landlady at the harbor. One drop of seawater would kill it, the woman had said, before giving it to someone bound for the sea. Sera brushed soil from its leaves and put it inside the window.
“Is that for eating?” Tio asked from the doorway.
“For keeping alive.”
“Hard work here.”
He went away and returned with a broad wooden dish, the sort that wouldn’t tip when a boat rolled. She put the pot inside it. Somehow it comforted her that even a room with a steady floor could need such a dish.
At the bottom of her chest lay the form on which she had listed her preferred postings. She folded HARBOR DUTY out of sight and used the back for that day’s notes.
Lunch was salty soup and dark bread. She was told twice not to feed the goat. Its name was Candleholder, because it had once climbed to the lantern room and eaten the wax.
“Three jobs in a lighthouse,” Varen said. “Tend the lightstones. Watch the lanes. Bring people home.”
Sera paused with her spoon in her hand.
“What about opening new lanes?”
“Can’t do that alone.”
He placed two crumbs on his plate, well apart. One was the lighthouse, he said, and the other an island.
“Look from only one side and the distance shifts. Two places must watch the same thing and record the same time. If the sea accepts both observations, the space between holds steady for a while.”
“I’ve studied how lanes are fixed.”
“Then you’ve studied how short ‘a while’ can be.”
She didn’t answer. The textbook said it depended on the tide and the condition of the lightstone. That didn’t tell her how long a real boat needed to come home.
After lunch he took her to the lantern room. She washed her spoon before following. She wanted to be useful in her new post. She didn’t want to prove it by pretending to know things she hadn’t learned yet.
They climbed slowly. Matching Varen’s pace, she noticed fine scratches in the tower wall: dates, years, people’s names.
When she tried to read them, he said, “Watch your feet on the way up.”
A round stone floated in the center of the lantern room, about the size of two fists together. Tiny ripples moved within its clear surface, as though it held a piece of the daytime sea. Light passed from it through large glass panels and out across the water.
One panel was cracked. A cloth covering the crack fluttered softly.
“Two reserve stones,” Varen said.
Two clear stones lay in a wooden box on the shelf.
“When they cloud over, they need three days in sunlight. Longer under cloud. Use one all night and you can’t use it again the next morning.”
She drew back the hand she had begun to reach out.
“What should I do today?”
He indicated a little table by the window. Four paperweights held down an old chart.
“Check the southern passage before the boat leaves. Tell the captain the wind has changed.”
At last, work she had been waiting for.
She mounted the angle instrument on the window frame and aligned the lighthouse reference point with the southern rocks. Fog hid the harbor beyond, but the positions of three rocks matched what she had learned from the textbook.
She wrote the readings.
Her hand shook on the first. The second was better. On the third check, the farthest rock had moved a little to the left.
She rubbed her eyes. A sea where rocks went walking was new to her.
She marked a dot in red instead of black. She felt Varen watching, but didn’t erase it.
“Why a different color?”
“The repeated readings didn’t agree.”
“Good not to hide an error. Don’t decide what caused it too quickly either.”
He pressed one of the instrument’s feet. Damp had swollen the wooden frame and tilted the mount ever so slightly.
Sera bit her lip.
He didn’t tell her to erase the dot. He had her write INSTRUMENT ERROR beside it.
Once she secured the mount again, the farthest rock stayed where it belonged. She let out her first relieved breath.
Then the bell sounded.
Low and long.
She looked up. Varen turned to the window too. The sound came from the east, not the southern harbor. Too low to seem merely carried on the wind. She felt it through her soles, as though the whole tower rang.
Once.
A pause.
Twice.
Varen took her record sheet.
“Time.”
“Past the fourth afternoon mark on the sundial.”
“Precisely.”
She checked the sandglass and noted how much sand remained. Tio came running up the stairs.
“Did you hear? Even the pier shook.”
Varen took a chart from a drawer. A thick line crossed out an island to the east. Maru Island. Lane withdrawn three days earlier.
Sera knew the name. She had been taught that the last residents had left, that no one remained.
The bell rang again.
A distress signal, pulled by human hands.
Varen uncovered a small round reflector. He turned sunlight through the window: one long flash, two short.
A tiny glimmer answered across the sea.
Tio drew in a breath.
“Someone’s still there.”
Sera marked Maru Island with a red dot. It could still be wrong. This time her hand didn’t shake.
Varen pointed toward the pier.
“Get the captain. We need the boat to stay tied up.”
Tio ran.
Sera turned the instrument east. A thin silver band hung over the sea. At first she thought it was sunlight. But sunlight didn’t stay in one place that long.
At its end, Maru’s rocks showed faintly.
A seabird crossing between them lurched sideways.
Its wings kept beating, but its body was pushed the other way. A second bird lost its bearings at the same point. Waves layered over one another against the wind.
A fold.
A phenomenon the textbook had marked with a single red line was happening in front of her.
She looked down at the southern chart. The fixed lane symbols glowed faintly in the lighthouse beam.
One line broke.
The ink remained. Its light was gone. A white gap opened halfway along the route to the southern harbor.
Nume’s shout rose from the pier.
“Varen! Southern passage is closing!”
Pen still in hand, Sera hurried to the window. The lighthouse beam bent halfway across the water. The moored boat strained its ropes. Nume was lowering the sail.
The boat couldn’t go home.
On Maru Island, the bell kept ringing.
Varen opened the box of reserve lightstones.
“Cartographer.”
For the first time, he left off “apprentice.”
“Ready to draw a lane you don’t know?”
Sera tightened her grip on the red pen.
“We have to draw the way back too.”
He lifted one clear stone.
“Yes. That’s the harder part.”