I suppose it was the moth-and-the-flame thing.

'I'm meant to be at rest, yes, but on the other hand Tilson said it was fully urgent and the signals room sounded like an electric organ when I passed it just now, and it's got me interested.'

I was the moth.

In a moment he said slowly, 'This mission has, shall we say, potentially major dimensions.'

And that was the flame.

'Sticks out a mile,' I said.

I was unaware of the pulse in the carotid sinus, and that was normal at a time like this; but the psyche is more subtle than the cardiovascular system and I didn't know whether the elevated pulse was because of excitement or fear.

'Holmes,' Tilson said, 'has asked the switchboard to put their call through to his own office, to yours, and to Mr Croder in Signals.'

Hyde prodded his tongue into his cheek and in a moment said, 'And Mr Shepley is monitoring?'

'Yes, sir.'

'Very well. I think,' he said, turning to me again, 'I'm going to do something rather nasty. I can't, you see, tell you anything useful about this one until and unless you have agreed to do it.' Watching me carefully.

'Oh for Christ's sake — you want me to go in blind?'

Dipping his head, 'Not quite. To go in under whatever conditions you care to name, provided of course I can meet them.'

The pulse went up again by a few more beats, and the bloodstream became palpable, like a quiet fire coursing through the veins, not unpleasant. Not much more than an hour ago I'd been asleep in bed, the sores and the spectres of the last mission still lingering but not offering any threat: I'd been safe; and now I was standing in this room with the choice of going or being safe for a little time longer, at least a few weeks, or letting these people pitch me headlong into the field again, of signing that form, the next-of-kin thing, without even knowing what I was taking on.