Naomi wouldn’t have discovered the note until the following morning if she hadn’t been wrenched from her sleep by the turbulent sea. In the well, too, she clearly felt it when the waves were rough, which is why she knew she was still on the ship, rather than having been transferred to a container somewhere.

Naomi couldn’t understand what was happening to her. How she’d got here. Or why.

After the note at the end of her bed, the last thing she remembered of her life was an open door in her corridor on deck 9, diagonally across from her own cabin. She’d thought she could hear Anouk crying. She’d knocked and called her daughter’s name. Poked her head through the door.

After that… blackness.

From that point on her memory was as dim as the hole she now found herself in.

‘What’s the worst thing you’ve ever done?’

She had no intention of giving the spider an answer. In her imagination it wasn’t a human being up there at the edge of the well, but a fat, hairy tarantula operating the bucket.

‘Where’s my daughter?’ she’d typed into the computer, replying with her own question. Naomi had shut the laptop and put it inside the plastic bag (she’d soon learned why the bag was there – the bucket wasn’t always cleaned) and tied it to the rope.

The answer came half an hour later:

‘She’s alive – safe and well.’

Naomi demanded proof. A picture, a voice message, anything. But the spider refused to grant that wish, upon which Naomi sent the notebook back up with the words: ‘Fuck you’.

As punishment she had to go twenty-four hours without water. It was only when, crazy with thirst, she started drinking her own urine that a new bottle was lowered. Since then she’d never dared insult the spider again.

This was another way in which the bucket system worked brilliantly: to discipline her. Punish her.

The second, more gruesome punishment, as a consequence of which she would probably perish, wasn’t imposed until much later. Because of her first confession.

‘What’s the worst thing you’ve ever done?’

She hadn’t answered the spider for seven weeks. With her intelligence – she did, after all, teach biology at an elite university – she’d compiled hypotheses, evaluated her options, analysed opportunities. Rather than blindly giving an answer.

Not me. No.

Naomi rocked her head forwards and back, and scratched her neck. Movements she was already making unconsciously.

Her hair was gradually falling out; it stuck to her fingers when she ran them over her head. She was pleased there wasn’t a mirror in the well. It also spared her the sight of the worms that were crawling beneath her skin.

Fuck, I had to eat that rice.

Nine days ago. She would have starved otherwise.