‘It is difficult to know what to do in that regard,’ he says, more to himself than the Dean or Thomas. ‘I am not yet sure of where Sir Giles stands in respect to his obligations to our house.’

Brother Anselm arrives with the reed and ink and this decides the Prior.

‘Nevertheless,’ he says, taking the nib and paper. ‘Let us do so, and see what results.’

‘Brother Robert can deliver it.’

The Prior nods and the Dean turns to Thomas.

‘Climb the belfry, Tom, and see if your men are still there.’

Thomas hurries through the secretarium into the nave, where Brother Barnaby is tugging the bell rope in sharp jerks. Thomas has never been up the ladder. His clogs are clumsy on the rungs and he clings to the risers so tightly that sections of bark come loose and spin down on Barnaby below.

‘Ave Maria, gratia plena, Dominus tecum. Benedicta tu in mulieribus . . .’

After almost a hundred rungs the ladder emerges through a trap door on to a bird-shit-splattered, roughly adzed wooden floor. The bell swings close above him, deafening. He crawls across to the snow-capped sill of the window set in the northern wall and looks out.

Nothing.

Beyond the priory walls a milk-white dawn mist has risen above the fens, a membrane that floats over everything so he can hardly tell where the earth below meets the sky above. Only the stark branches of the hawthorn trees are prominent, though here and there the mist eddies and thins under the tutelage of the freshening wind, so that vague shapes appear for a moment, then are gone.

He watches from the other windows of the tower, each facing a different point on the compass, and through each the view is similar. There is no sign of the horsemen. Down below he can see the beggars’ gate open and quickly close again to admit numerous lay brethren, summoned from their granges by the din of the bell.

At length it stops ringing, though his ears continue long after.

‘Brother Thomas!’

The Dean is standing in the middle of the garth, framed by the cloister.

‘Anything?’

‘Nothing, Brother!’

From below comes the clop of iron shoes as a horse is brought across the cobbled yard. Perched atop is the reluctant Brother Robert.

The Dean calls up again.

‘Is the road clear?’

Thomas waits before replying. A clearing in the mist is drifting across the land, a window through which he can see the snowfields below. He waits until it reaches the road, bulking out and flattening against the dyke before rising and passing over, revealing only the weals left by the tracks of long-gone travellers.

‘No one,’ he calls down.