Shaking my head, I imagine Mason in his house, laughing as he looked out of the window and saw her car, knowing how easily he could get away from us. Getting my phone out of my bag, I call the DI. ‘Sir? Mason just left his house – by helicopter. He was airborne about two minutes ago.’ I listen for a moment, then hang up and look at Sarah.

‘He’s going to try to track the helicopter. Chances are, it won’t fly high enough to be picked up by radar.’ I knew he wouldn’t make it easy for us. Mason’s too sharp to let himself get caught. ‘Do you hear that?’ I catch Sarah’s eye just as a car comes into view. Reaching us, it pulls up and a young man in a suit gets out.

Imagining another of Mason’s potential investors, I show him my badge. ‘DS May. Chichester Police. Have you come to visit Philip Mason?’

The man looks uncertain. ‘I have an appointment with him.’ He looks at his watch. ‘In ten minutes.’

So we had interrupted Mason’s plans to stay around. ‘May I ask if you’ve come here to discuss a business investment?’

He frowns at me, then glances at Sarah. ‘I wouldn’t call it that.’ He pauses. ‘I’m an estate agent. I’ve come to value his house.’

As Sarah’s eyes meet mine, I ask quickly, ‘You have a key?’

‘As it happens, I do.’ He looks at us suspiciously. ‘Mr Mason did say that in the event that he got held up, I was to make a start with the house.’

‘Can you give me a minute?’ I nod towards Sarah, and pick up my phone again to call the DI back. The call goes straight through. ‘Sir, Mason’s arranged for an estate agent to let himself in to value the house. He has a key.’

‘Stay where you are. I’ll get an emergency search warrant organised. I’ll call you back.’

Ending the call, I nod towards Sarah, then the estate agent. ‘What’s your name?’

‘Adam Matterson.’

‘Thank you, Adam. That was my boss I was speaking to. We’re waiting for a search warrant, then he’d like us to go in with you.’

Adam looks taken aback. ‘I’m afraid I can’t let anyone else in with me. Mr Mason was most explicit when I spoke to him.’

‘We’ll just wait, shall we?’

*

It isn’t long before the DI calls back. ‘Get in there, May, and see what you can find.’

‘Yes, sir.’ I turn to the estate agent. ‘OK. Shall we go in?’

He looks awkward. ‘I’m not at all happy about this.’

‘Mr Mason is wanted in connection with a serious criminal offence.’ I pause, not taking my eyes off him. ‘I’m afraid you don’t have a choice.’