He ushered her briskly out and strode off.

She was alone in the corridor.

3

A small brown photograph

Shake and rattle, test and weigh

You can’t measure the heart’s dismay.

Seren gazed after him. Then she began to walk slowly towards the schoolroom.

What was going on? Those forms and papers worried her. They reminded her of interviews with inspectors at the orphanage, who were always big men in dark suits and top hats, who wrote things down gravely and shook their heads a lot.

A sharp whistle made her look up.

Tomos was peering round the schoolroom door. ‘Where have you been? He says, fetch that Box. But be careful and wear gloves.’

Seren sighed. Sometimes the Crow was just silly. She ran to her bedroom, put on her church gloves and picked up the Box carefully, wrapping a shawl around it just in case. Then she hurried to the schoolroom.

‘Put it down there.’ The Crow flicked a wing at the cleared table.

Seren did. She stepped back. ‘What shall we…?’

‘Lessons first,’ the Crow snapped. ‘Box later.’

She frowned at Tomos. They both knew the Crow was itching with excitement to examine the Box, but this was just like him, to pretend it was an ordinary day with nothing unusual going on.

For five whole minutes they tried to do Latin translation. But Tomos got the tenses all wrong and Seren forgot the words and even while the Crow tutted and strutted, its bright eye kept straying to where the dark Box lay shimmering in the sunlight on the table.

Finally Seren threw down her pen. ‘This is just totally silly! No one can concentrate. Let’s get on with it!’

The Crow managed half a second of looking cross. Then it flipped the chalk it was trying to write with across the room. ‘Kek kek,’ it said. ‘You’re quite right. Come on.’

It flipped across to the table. Tomos slapped his notebook shut and hurried over. They gathered round the Box.

Seren put out her hand but the Crow slapped it back. ‘NO! This could be dangerous. We have to conduct a thoroughly scientific investigation.’

Tomos grinned but the Crow was deadly serious. It hopped all around the Box, tipping its head and eyeing every inch of the sides.

Then it jumped back.

‘Scales,’ it demanded.

Seren carried the heavy weighing scales over to the table.

‘Put it on.’

She put the Box in one pan and some weights in the other, until the pans were level, and Tomos read the weight on the scale. ‘Twelve ounces.’

‘Heavy. Write that down.’

Seren grabbed a pencil and scribbled it on an empty page. Then she wrote THE BOX OF THE MIDNIGHT SWAN on the top, just for a heading.

‘Measuring tape!’

Tomos ran for it. The Crow took one end in its beak and stretched it out, but got it all tangled round his talons. ‘Drat!’

‘Let me.’ Tomos measured the Box carefully. ‘Nine inches by seven inches. And three inches deep.’