Margaret laughed. ‘Oh, you’d be surprised. There are a good many who are full of rip-roaring enthusiasm right up until the moment they actually have to begin to get stuck in and do some genuine hands-on research. Then suddenly almost anything seems to be more appealing than spending all their waking hours in the dark recesses of a museum store or surveying a windswept hill fort in the teeth of a howling gale.’

‘But Beth wasn’t like that.’

Margaret shook her head. ‘No, she couldn’t get enough of her subject. In fact, that was how I first got to know her. She pestered the living daylights out of me at every conference I attended. I have to confess after a while I got heartily sick of it. I began to avoid her.’

Clare looked shocked. ‘You mean she was some sort of stalker.’

‘I wouldn’t put it quite like that, though she didn’t really mix much with the other post-grads. No, she was more a sort of academic groupie. And it wasn’t just me. She was like a sponge. She would hang around questioning anyone who appeared to know anything at all about the Iron Age and Celtic studies.’

‘So, she was genuinely committed to her subject, then.’

‘Unquestionably, but one can take commitment too far. Look at how she chose to end her life.’

‘Before her suicide, would you have said she was obsessive?’

Margaret considered for a moment. ‘You have to remember most of what I’ve been talking about was the best part of a quarter of a century ago. But no, I don’t think I would. She wasn’t what David would so eloquently refer to as “a nutter”. At least not in her student days. I bumped into her at various events in the intervening years, and of course I’ve read most of her work since then. And there’s no doubting the brilliance of her academic work. But I never really knew her on a personal level. I’m not sure that many people did. She was very’ – she hesitated, searching for the right word – ‘well, intense. And very private.’ She sat silently for a moment, allowing her gaze to drift across the quad to the lilac-blue wisteria nodding its agreement in the late afternoon breeze. ‘I am certain of one thing, though – something must have happened to make her leave her post at Sheffield.’

Clare looked at her quizzically. ‘What makes you say that?’

‘Well, she’d been in the department there for years. She was one of their leading lights. And then suddenly, completely out of the blue, she upped and left with absolutely no explanation.’

‘Left or was asked to leave?’