‘The pathologist explained that the diatoms in her blood did not match those in the water where she was found.’ Barrett stared blankly at Palmer. ‘Oh, yes, that was my reaction too,’ Palmer chuckled. ‘Diatoms are tiny animal life forms that live in the waterways. The same way a soil sample will differ from one field to another, so will the diatoms in the water. The pathologist is going to head out and take a number of samples from further up the river, to see if they can conclude where the body went in. The other thing the discovery of the diatoms means, is that she was alive when she went into the water. Had she been dead, there would have been no blood circulation, therefore, no diatoms could have ended up in her blood.’ Barrett nodded, following every word as closely as he could. ‘Having said that, the pathologist confirmed there was blunt trauma to the skull, and the victim would have died as a result of a brain haemorrhage had she not drowned first. In other words, she stood no chance.’

‘How quickly will the pathologist be able to collect and analyse the water samples?’

‘She said that she and the SOCOs are going to do that this evening. They should have the results by tomorrow. She also said that there is no evidence on the body that Toni Jones was raped, and that, because so much time has passed since the alleged rape, it would have been unlikely that there would be any sign anyway.’

‘Okay.’ Barrett got up and did his typical thing of pacing back and forth. ‘We have two more people to interview. I’d like to speak to Amy Martin first. Let’s leave Mrs Grubb until last.’ Palmer knew Barrett’s reason for doing this was because he didn’t relish the prospect of potentially having to break it to the woman that her husband was a scoundrel.

‘Yes, sir. She lives on Mawson Road, off Mill Road. It’s a five- or ten-minute walk.’

‘Good,’ Barrett said, looking out of the window. ‘I like a late afternoon stroll in the sun.’

The walk from Parkside police station to 102 Mawson Road was not quite as pleasant as Barrett had hoped. Mill Road was bustling with students out enjoying the sun, and people sitting on the street, outside cafés, drinking coffee and having a bite to eat. It was also busy with bikes, and the cyclists had no concern about riding on the pavements, despite the number of pedestrians they endangered and had to swerve around. By the time the detectives arrived, Barrett was once again in a grump.

When the red front door opened, both men were slightly surprised to see a pregnant woman in her thirties. She looked tired, and did not offer more than a brief smile to the strangers.

‘DCI Barrett.’ He held up his badge. ‘Are you Mrs Amy Martin?’