‘I just need to freshen up after that workout.’ She giggled.

Jane slowly pushed the slide catch on the door to lock it.

‘Fancy a glass of Scotch?’ Kingston asked as he opened the squad room door.

‘No thanks, I’m warm enough already,’ Katie said, trying to open the toilet door. ‘Is someone in there? It better not be you, Stanley, or so help me God I’ll rub your nose in anything you’ve left on the seat!’

Jane was in two minds about keeping quiet, hoping Katie might think the door was jammed and give up, but then decided she shouldn’t have to skulk about because of their outrageous behaviour.

‘It’s me, Jane Tennison – is there a problem?’

‘Oh, right, I thought it was Stanley. How long have you been in there?’ Katie asked sheepishly.

‘I just got back and was desperate for the loo. I’ll be finished in a minute if you’re waiting.’

‘It’s all right, take your time.’

She grabbed her hairbrush and went into Kingston’s office.

‘Tennison’s in the loo.’

‘What’s she doing back here?’

Katie started brushing her hair. ‘I don’t know . . . I think she may have heard what I just said to you about being warm already.’

‘So what? She doesn’t know what we were up to, but she will if she sees you all flustered. Just calm down and act as if nothing’s happened.’

Katie returned to her desk, sat down and started typing.

‘Toilet’s free now, Katie.’ Jane walked into the office but Katie didn’t seem to hear her. ‘Are you all right, Katie?’

‘What makes you ask that?’

‘You seemed to be in another world, that’s all.’

‘The heating’s playing up again – it’s so stuffy in here it’s making me feel nauseous.’

‘Is DI Kingston in?’

‘Yes, he’s been in his office all evening doing paperwork,’ Katie replied as she hurried off to the toilet.

Jane thought that even if she hadn’t seen Katie in the gym with Kingston, she’d have guessed something was up. Guilt was written all over Katie’s face. She might be good at filing, but she was a lousy liar. Jane would have loved to have made a sarcastic comment but bit her lip, knowing it could backfire on her if Katie said anything to Kingston. When she entered his office, he was sitting at his desk writing, with a glass of whisky next to him.

‘I didn’t expect to see you back here tonight, Tennison. Something of interest come up?’