Not good news. Not good news at all. I began pacing the carpeted cell. After several dozen crossings and two Players, I came to a conclusion: I’d have to go it alone - without back-up, without sanction, and probably with Pritchard in the same field.

The first thing to do was to write a note: something for them to get their teeth into, something that would appeal to their Boy’s Own view of the world. When I’d prepared a few suitably indignant lines, I dug out the Service’s Operations Manual from a drawer and looked up which vaccines and certificates were needed for Nigeria. These turned out to be yellow fever and smallpox, so I took out the forms and spent the next ten minutes carefully filling them in, making sure the dates were well within the prescribed time. Nigeria being a former British colony, no visas were needed. Then I placed two calls: one to a travel agent in Holborn, and the second to a number in Fleet Street, where I asked to be put through to someone in the newsroom.

‘Dobson,’ he answered. He sounded tired and a little angry. Not especially propitious.

‘Joe!’ I said, putting all the chumminess I could muster into my voice. ‘It’s Paul. Paul Dark.’

‘Paul, me old china!’ he said, more jovially. He liked to play up the old cockney wag act, even though his father was a barrister in St John’s Wood. ‘Long time, no hear. Got a scoop for me?’

It was a joke, of sorts - I wasn’t a journalist, and he was reminding me of the absurd nature of our relationship - but at the same time he was being serious. He wanted to know if I did, indeed, have a scoop.

‘I can get you one,’ I said, ‘if you return a favour.’

He laughed. ‘You owe me a few, don’t you, mate?’ After a moment or two, he bit: ‘All right. What can you get me, and what’s the favour?’

‘Something big is about to happen in Nigeria,’ I said. ‘I need to be there.’

‘Nigeria? Since when was that your field? You been shifted to the Africa desk and not told me?’

‘No, nothing like that,’ I said. ‘I just need accreditation - that’s all.’

‘Paul, old son, you do know there’s a civil war on there?’ I said I did, and he harrumphed. ‘We’ve got three stringers out there already. I don’t see how I could justify another. It’s not like BOAC will just fly you into the jungle . . .’

‘I don’t want to fly into the jungle. I want to fly to Lagos.’ I listened to the sound of prolonged wheezing. ‘Nice try, but April Fool’s ain’t ’til next week. There’s bugger all fighting in Lagos - even I know that much.’

‘Yes, but that’s where the story is. Trust me.’