‘It certainly fits his symptoms,’ Oliver said. ‘The question is how.’
‘It can’t be something burned on the fire in St John’s bedroom – the rest of the household would have been affected when they entered the room.’ She shook her head. ‘But if you’re right, what I can’t understand is why. There are only four people with access to him and I cannot fathom which of them would do such a thing.’
‘That doesn’t mean none of them would,’ Oliver pointed out. ‘I’ve tried plenty of cases where the perpetrator seemed entirely innocent, in spite of the mountain of evidence proving their guilt.’
Harry shook her head again. ‘I don’t understand what they’re trying to achieve. An accidental overdose of his sleeping draught would be an easier death, if one of them wanted him dead. But who would benefit from it? Not the domestic staff – they run the risk of losing their jobs, and the roof over their heads. And not Archer – he positively dotes on his uncle.’
Oliver sighed and changed down a gear as he took on a particularly jagged corner. ‘Although he is also an accomplished actor – perhaps his affection is just another act. No, don’t argue with me; let’s consider this logically. Who has the opportunity to poison Philip St John?’
‘Any of them,’ Harry said, after a moment’s consideration. ‘His bedroom is on the first floor, easily accessed without arousing suspicion. He eats separately from Archer, so it would be easy to add something to his food. The sleeping draught is usually dispensed by Agnes, the housekeeper, but I don’t think it is kept under lock and key so any one of them could have doctored it with a little extra something to tip him over the edge. It’s a shame I couldn’t get a sample – we might have had it tested in London.’
Oliver glanced at her. ‘You’re stuck on the notion that the crime is the action of a single person – what if there is more than one person involved in poisoning him? What if it is a conspiracy?’
She reviewed what she knew of Agnes, Mary and Donaldson. ‘If that is the case, they are all extremely talented actors. Slow down – you need to take this left.’
He braked, slowing the car and steering into the road she indicated. ‘So that’s opportunity settled,’ he said, ignoring her objection. ‘What about the means?’
‘Hard to say when we don’t know what’s being used to poison him,’ Harry said. ‘But if it is the sleeping draught then it doesn’t narrow things down. Any of them could have tamperedwith it at any time. And then there is the small matter of last night’s hallucinations, which got worse when hedidn’ttake the medicine.’
‘Who served him his meal?’
‘Agnes,’ Harry said. ‘Although Mary prepared it and Donaldson was inside the house. Archer was with me most of the time but not always. Again, if there’s something in his food, anyone could have added it.’
Oliver frowned. ‘Then we should consider motive, although you have suggested no one stands to gain by Philip St John’s death, at least at first glance.’
‘It’s likely Archer would inherit Thrumwell Manor but he already lives there – why would he need to inherit the house sooner?’
‘Who knows?’ Oliver said. ‘Perhaps he has gambling debts he needs to pay.’
Harry raised her eyebrows. ‘Was there any evidence of that when you enquired about him at the Garston Club?’
‘No,’ Oliver admitted. ‘He doesn’t even play cards, from what I was told. What about the others?’
‘Agnes has been at Thrumwell Manor longer than St John,’ Harry said doubtfully. ‘She was still very young when he bought the house. I suppose it’s possible that his behaviour towards her has not always been proper, although she gave no sign of it, and I can’t imagine why it has taken her so long to extract this rather convoluted revenge.’
‘An excellent point,’ he said. ‘In the cases I’ve seen like that, the victims usually snap out of desperation or in self-defence. They lash out with whatever comes to hand; they don’t often drive their abuser to the brink of insanity with a cunningly administered poison. What of the cook?’
Harry shrugged. ‘Without her position at the house, she would have nowhere to live.’
‘The groundsman, then,’ Oliver said. ‘He only joined the household recently. Maybe there’s more to him than meets the eye.’
Harry thought of no-nonsense Donaldson, who had helped to carry Philip St John from the fen on two occasions. ‘Wouldn’t he have just let St John drown?’
Oliver grunted. ‘So none of them have a motive,’ he exclaimed in frustration. ‘But someone is poisoning him. How can that be?’
Harry considered the problem thoughtfully. ‘Whoever it is, they don’t mean it to be the cause of his death, or he would be dead already. I think they mean to make it look as though he died by his own actions.’ She paused to glance across at Oliver. ‘And they don’t care how much he suffers beforehand. That suggests revenge of some kind.’
‘For an act we have yet to uncover,’ he added, and groaned. ‘This is making my head hurt. I’m not sure we’re any further forward than we were before.’
‘Mine too,’ Harry said, sighing. ‘And in the meantime, Philip St John’s life hangs in the balance.’ Realising she had not been concentrating on their route, she glanced down at the map. ‘I think Morden village is up ahead, if you want to stretch your legs.’
Oliver winced. ‘It’s not my legs that are the problem, it’s my back. I’m not sure I’m cut out to be a chauffeur.’
The village was as tiny as Harry remembered from her fleeting glance the day before – just a cluster of houses on either side of the main road. A shop overlooked a triangular village green, facing a pub on the other side, both of which were closed. Harry pointed to a wooden table and chairs outside the pub. ‘It doesn’t look like we’re going to get a drink but we could sit over there.’
On impulse, she brought the map and spread it over the table. ‘We’re here,’ she said, pointing to Morden village. Her finger slid across the paper. ‘And there’s Thrumwell Manor, right in between the villages of Burwell and Morden. Agnes said there’s a shortcut across the fens but I can’t see it marked on here.’
‘Hardly a surprise, since she said it was an informal route,’ Oliver observed.