‘Difficult to say for sure. According to this account it was “happened upon in the garden of Bailsgrove vicarage” when the new vicar took over the living. But the story he had from the housekeeper was that the previous incumbent had found it “somewhere near the foot of Bailsgrove hill”.’

David said, ‘Thoroughly reliable source, then.’

Margaret said, ‘You shouldn’t be so quick to dismiss these old accounts, David. There’s often more than a grain of truth in them.’

Clare said, ‘That’s all very well. But what do you make of the inscription on it? I don’t read Latin.’

David said, ‘It looks like a dedication to Mercury.’

‘But Mercury was a Roman deity.’ Clare sounded almost deflated. ‘Beth was wrong, then.’

Margaret shook her head, ‘Not necessarily. The Romans had a habit of twinning their gods with those of the native Brits. You know Bath was originally called Aquae Sulis.’ Clare nodded. ‘Well, Sulis was a local water deity, but in the temple they built at the spring site, the Romans worshipped her as Sulis Minerva.’

Clare said, ‘A sort of Romano-British mash-up.’

Margaret said, ‘If you like.’

David said, ‘Some might call it identity theft.’

In his opinion the Romans were much overrated and the best thing they ever did was bugger off home. It was just a shame that it had taken them four hundred years to do it.

Margaret was obviously of a different mind. She turned towards Clare, studiously ignoring his remark. ‘The thing is, Mercury is one of the gods that is frequently twinned with local deities. In his case it’s often Lugh, the native sky god.’

‘So, Beth might have been on to something.’

Margaret said, ‘It’s possible.’

David said, ‘Oh, come on. It’s hardly proven beyond doubt, is it? We don’t know for sure that thing’ – he jabbed his finger at the drawing – ‘actually came from anywhere near Bailsgrove, let alone this site. And even if it did and there was an Iron Age shrine somewhere near Bailsgrove, there’s no hard evidence to suggest it was here.’

Margaret cast him a withering look. ‘It’s always wise to keep an open mind about these things. And there’s only one way we’re going to find out. Clare here needs to get on and dig it.’

‘Well, that at least we can all agree on.’

As David stepped down from the welfare unit, Margaret placed a hand on his shoulder and leant down to whisper in his ear. He was expecting a lecture on his attitude to Romano-British relations, but instead Margaret’s concerns were somewhat more grounded in the present. ‘I do hope you’re not intending to let Clare pay for that exhaust, David. You know she’s not as financially well-placed as either of us. If you don’t reimburse her, I will.’