As they dragged themselves towards the nearest stairwell, Tarquinia recounted her own misadventure. ‘They let me have the observing time, and everything was looking perfect, but then the most officious busybody among my colleagues decided to check in on me just when I was inspecting the jetpack from the emergency kit. She decided that was suspicious enough to execute a citizen’s arrest; most of the other staff thought she was an idiot, but she had an ally. I was afraid that if I was released, the two of them would be disgruntled enough to make a real effort to get the attention of someone with the power to mention the incident in an official message.’

‘And then the Council would have known from the start.’ The whole crew would have been under close surveillance from the moment the Surveyor arrived.

‘Exactly.’ Tarquinia buzzed. ‘So I ended up having to let myself be detained in a room at the observatory, with the idiots kept busy watching over me and arguing with my colleagues who wanted me released. It was only after the disruption that they managed to get the security department involved.’

They’d reached the level of the hospital; it was just a short walk up-axis now. Ramiro said, ‘Before we see Agata, there’s something I need to tell you.’ He explained his debunking of the hoax. ‘Don’t be angry with me,’ he pleaded. ‘The whole thing about the ancestors was making her crazy.’

Tarquinia said, ‘I’m not angry, but you shouldn’t have told her that.’

‘Why not?’

‘I didn’t make the inscription,’ Tarquinia declared. ‘I went out there to try, but nothing happened: no shards of stone rose from the ground to meet the chisel. I tried different tools, different movements . . . but I couldn’t unwrite those symbols. If anything, when I left they were sharper than I’d found them – as if all I’d done was make the message less clear for Agata and Azelio than if I’d stayed away completely. I wasn’t the author of those words. Someone else must be responsible for them.’

Ramiro didn’t know if she was telling the truth or just trying to hold on to the benefits of the hoax, but he wasn’t going to start questioning her version of events now. If this was her story, there was nothing he’d seen with his own eyes that contradicted it.

When they entered the hospital ward, Agata caught sight of Tarquinia and called out excitedly, ‘Ah, you’re free! Congratulations! Come and hear some great news!’

As they approached the sand bed, Ramiro could see that Agata had gained some flesh since his last visit, but she was still limbless. The doctors had told him that she would need every scrag of tissue to support her recovering digestive tract.

‘What’s the news?’ Tarquinia asked her.