Jasper's first letter home began with a sentence his mother had specifically forbidden. Dear Mum and Dad, I am alive. He stared at it, remembered his father's suggestion that four words ought to be the minimum acceptable proof of survival, and added: and school is good. Ava leaned across the shared desk. "That is not a proper letter."

"It is on paper and addressed to people."

"It contains seven words."

"That's more than four."

Harper, who was lying upside down on her bed with her own paper on the floor beside her head, said, "Mine starts, Dear Mum, Tidefall hasn't killed me yet." Ava looked between them. "Both of you are terrible at this."

Sunday evenings had become unofficial letter hour in West Residence. Nobody called attendance, but Mae walked the corridor with envelopes and stamps while saying things such as your family misses you more than you think, which had much the same effect.

Room Fourteen already looked less temporary than it had on the first day. Jasper's books occupied the shelf beside his bed. Ava had arranged one side of the desk with pens, labels and a small ruler that she used more often than any ruler deserved. Harper's belongings followed a system that was not visible to the human eye.

Bag Bed had evolved beyond bags. It now held two library books, Harper's spare shoes, a shell found in a courtyard drain, a broken practice target Jasper had decided was worth keeping, and a box of lamingtons from home. One lamington remained. Its ownership had become constitutional. Jasper returned to his letter.

He wrote about the boat, the stairs, the room and the fact that Harper could move things much farther than instructed while Ava became annoyed when hers moved two centimetres instead of one. He described Ancient Selari and admitted that he had already drawn one character backwards often enough for Professor Ilyan to recognise the mistake from across the room. Then he stopped. Ocean Studies sat in his mind like a sentence waiting to be written. His mother had told him to mention unusual magic. Jasper had promised. Unfortunately, the truth looked much worse when placed on paper. He wrote carefully:

The sea did something strange during class. Nobody was hurt. Headmaster Thorne asked me about it because I felt something before it happened. He says there are old records of similar things and that I should tell a teacher if it happens again. Jasper read the paragraph twice. Harper appeared over his shoulder. He covered the page. "Privacy."

"I wasn't reading."

"Your face was directly above the words."

"I was comparing length."

Ava did not look up. "Letters are not competitive." Harper went back to her bed. "Mine is still longer." Jasper expected her to tease him about the sea paragraph. She did not. That was one of the first things he learned about Harper: she joked about nearly everything, which made the moments when she chose not to much easier to notice. He finished with a request for more lamingtons because the previous packet had suffered unexplained losses. Harper objected to the word unexplained. Ava objected to the word losses because she had eaten two herself and considered them properly accounted for.

After dinner, the three carried their letters downstairs. West Residence used an ordinary brass post box enchanted only to mark outgoing mail and prevent students from removing somebody else's envelope. Harper found this disappointingly practical.

"Why not instant messages?"

Mae looked up from her book. "Because seven-year-olds do not require a magical method of contacting their parents at two in the morning."

"Phones already do that."

"Which is why first-year device rules include night storage."

Harper considered this a personal attack on civilisation. The next two weeks passed quickly enough that Jasper stopped measuring Tidefall against home every hour. He learned which staircase reached Foundations fastest and which one looked faster but somehow added two corridors. He learned that the dining hall porridge improved dramatically if buried under brown sugar, that Professor Elowen could tell when somebody had stopped paying attention even with her back turned, and that Ava preferred library alcoves facing inland because the sea distracted her. Harper said books distracted her. Soren, a boy from two doors down, walked into a pillar while reading and proved both of them right.

Magic became more difficult in small, satisfying steps. Cloth gave way to beads, beads to feathers, and feathers to holding two objects at different heights. Harper improved fastest in raw force. Ava was best at exact placement. Jasper sat somewhere between them, stronger than Ava in some exercises and steadier than Harper in others.

Ancient Selari remained less cooperative. Their class learned the words for water, school and magic, then spent an entire lesson discovering why three historical spell terms looked almost identical to beginners. Ava loved it. Harper announced that the ancient Tidefallians should have invented clearer vowels. Professor Ilyan said several dead scholars had made the same complaint. Jasper did not feel the presence again for nine days. He counted despite trying not to. On the ninth day, he and Ava were crossing Founders' Courtyard after lunch when the pressure brushed his chest. Jasper stopped. Ava walked three steps before turning. "What?" He looked between the pillars toward the western water. Nothing unusual moved there.

"It's back."

Ava did not ask what he meant. "Strong?"

"No."

"Anything happening?"

"No."

She took out her notebook. Jasper groaned. "Seriously?"

"Time?"

"Lunch time."

Ava checked the courtyard clock. "One twenty-eight."

"You don't have to record everything."

"I know."

She wrote it anyway. The pressure faded before they reached class. Jasper expected to feel disappointed. Instead, he was relieved. Something had been there without asking anything of him.

Letters became a rhythm of their own. The first reply from Jasper's parents arrived on Wednesday in a cream envelope with his mother's neat handwriting on the front and his father's much messier addition squeezed beneath it: PROOF WE ALSO REMAIN ALIVE.

His mum answered every detail in his letter, including the parts Jasper had not expected her to care about. She wanted to know whether Harper's excessive force was improving, whether Ava was always as organised as she sounded and whether Jasper's headache after Foundations had returned. She thanked him for telling them about Ocean Studies instead of hiding it. His father drew a terrible diagram of a wave wearing glasses and labelled it POSSIBLE SCHOOL ADMINISTRATOR. Jasper showed Harper and Ava. Harper said, "Your dad is correct." Ava said, "There is no evidence the wave wears glasses."

"You two are impossible."

The exchange made distance feel smaller. Tidefall still took his phone at night under first-year device rules, and long mirror calls needed scheduling, but letters created a different kind of connection. They made Jasper stop and decide what part of the week mattered enough to explain.

He began noticing things partly because he wanted to tell his parents later: the way rainwater ran through carved channels across Founders' Courtyard, the smell of bread from the kitchens before breakfast, the fact that Harper hummed when she was trying to concentrate and denied doing it when confronted. Tidefall became more real as he described it to people who were not there. Maybe that was allowed.