‘So, the part of the brain related to thinking and voluntary movement is asleep, and the movements they make are controlled by other parts of the brain and are sort of reflexive?’ asked Sam.

‘Exactly,’ Hughie said. ‘People can do amazingly complex things in their sleep, quite bizarre things sometimes, and have no memory of them afterwards. Listen, Sam, give Laura these studies to read and tell her that if she wants to discuss any aspect of the subject, I’ll be happy to talk to her.’ He grinned. ‘I’m a bit of an expert on somnambulism.’

‘Is it true that sleepwalking can run in families?’ asked Sam.

‘Yes, it can. You’re much more likely to sleepwalk if other members of your close family suffer from sleep disorders or night terrors. We’re pretty sure it has a genetic component, but we have yet to establish how the condition is passed down.’

‘You told me to remind you about the Reece case,’ said Sam. ‘I read the basics: Reece adored his sister and her husband, yet he apparently drove twenty miles to their home, where he brutally killed his sister and savagely attacked her husband. His defence was that the whole episode occurred while he was asleep. Is that right?’

‘You’ll find a brilliant paper from an eminent scientist/neurologist in the file,’ Hughie said. ‘It’s one of the most widely discussed trials in which somnambulism was used as a legal defence. The most remarkable thing about it was that Reece was acquitted. However, I’m in agreement with my colleague, who writes that a lot was missed at the trial, factors not brought to light that really should have been considered. Read it, Sam, it’s a bloody good insight into a mind on the rampage.’

Fascinated, Sam assured him he would.

‘You know about the state of dissociative analgesia that can occur in sleepwalkers?’ asked Hughie.

Sam nodded. ‘I’ve heard they can injure themselves and feel no pain at the time.’

‘In Reece’s case, immediately after the attacks he went to the police station to give himself up, arriving with badly slashed hands. He’d done it to himself but was completely unaware of having done so. This was a major argument in the case for the defence. He also registered serious abnormalities on an ECG.’ Hughie looked at Sam, eyes bright. ‘I’ll be very interested to hear your thoughts once you’ve read that paper. And you’ve whetted my appetite. I’m keen to learn about Laura’s new case. It’s perfectly possible to drive asleep, but thankfully not a common occurrence. She could have an interesting case history of her own there. I’d love to share it.’

‘I think she’ll be more than happy to do that. She didn’t say too much, but from the little she did, I could tell she’s worried about it. Very worried, in fact.’

‘Then tell her I’m all ears.’ Hughie passed Sam the folder of papers. ‘There you go. Bedtime reading.’

‘I really appreciate it, Hughie.’ Sam accepted the file gladly. He wasn’t often able to help his protégée these days, and he was pleased to have found a way. ‘I’m glad to have been able to tap into your fount of knowledge.’