The next day, Sarah sat on a bench in a churchyard close to the Thames. She liked it there. It was quiet and tranquil, which gave her time to think clearly.

‘I’m bored, can we go now?’ Tommy asked.

He’d been wandering around looking at the headstones, but now sat next to Sarah on the bench.

‘In a minute,’ she answered.

‘Can we go back to the bridge and look for more treasure?’

‘That was a bit of a fluke the other day. I doubt there would be anything else there now.’

‘Please, Sarah. It’s much more fun than sitting here with all the dead people in their forever boxes under the ground.’

He had a point, she thought, and reluctantly stood up to leave. She didn’t expect there would be anything in the mud again, but she’d humour her brother, if only to stop him moaning.

Battersea Bridge was just around the corner, and soon Tommy was racing off again to look over onto the banks. ‘Pick me up,’ he asked as he held onto the balustrades and jumped up and down.

Sarah lifted him up, and Tommy squealed in delight.

‘I don’t believe it, Sarah … there’s more treasure!’

‘Don’t be daft,’ she said, and placed him on the ground to look over the edge for herself. To her utter amazement she saw something glistening in the mud again, but she couldn’t believe it could be anything like what she’d found before. It was more likely to be an old tin can, she thought.

‘Told ya … I told you there’d be more treasure, didn’t I?’

‘Yes, Tommy, you did.’

They both ran to the steps and raced down to the foreshore. When Sarah got to the bottom, she noticed the water’s edge was closer than it had been last time. It was later in the morning, so she assumed the tide must be coming in.

‘Stay here, like before. I’ll go and get it,’ Sarah instructed, and set off across the mud. She’d never taken much notice of the river before now, and wasn’t sure how quickly the water would rise. She’d heard stories of people drowning in the Thames, so with her heart pounding she hurried to retrieve the item before it could get lost under the water.

‘Got it,’ she called over her shoulder to Tommy. She looked towards the water to see it approaching faster than she had anticipated. With no time to hang about, she made a hasty retreat to Tommy on the steps.

‘What is it, Sarah?’

‘I’m not sure,’ she said, looking curiously at the item in her hand, but she thought it might be valuable.

‘Can I see?’ Tommy asked.