The noticeboard

"Think about how Victor's mind works," Lina said. "He knew his room would be searched. Anyone who hides something in a drawer or behind a radiator expects it to be found by someone looking hard enough. So the cleverest place to hide it is somewhere nobody would bother to look."

On Wednesday morning, she knocked on the door of the student council room. Her excuse, a question about the photography club's budget, was a ruse. She had no interest in the budget at all.

Victor was charming. They talked about money and cameras while Lina let her eyes move slowly around the room. And there, on the noticeboard by the door, was a dirty brown envelope with a coffee stain on it. It was pinned up openly, among posters and lost-property notices, with "OLD FLYERS – RECYCLE" written across it in red pen.

The teachers had seen it. Everyone had seen it. Nobody had looked inside it, because nobody hides something important on a noticeboard.

The conundrum now was how to take it without Victor noticing. Lina came back the next morning with an identical envelope, stained and labelled the same way. Her friend Rahim knocked over a box of chairs in the corridor. Victor rushed outside, and in three seconds Lina made a deft swap: quick, quiet and perfectly smooth.

That afternoon, Mr Tan opened the envelope and found his mark scheme. He was incredulous. "On the noticeboard? In front of everyone?"

"That's why it worked," said Lina.

Victor had always loved being noticed, and his clothes and speeches were famously ostentatious. But this time, his own pride had defeated him: his plan had been audacious, and he had been sure no one was astute enough to see through it.

When the mock exam began on Thursday, Victor looked around the hall with a sardonic smile, as if the whole thing were a joke only he understood. Lina simply looked back. She felt vindicated. Her strange idea had been proved right. And the cryptic message she had left inside the fake envelope? It said only: "Check your noticeboard."