They stop in Tewkesbury that night where they find an inn named after the bells that sound compline from the square tower of the nearby abbey. While the others settle the horses, Katherine and Thomas linger by the dock, waiting in the shadow of some willow trees. There is nothing unusual to be seen, or at least that they notice.

‘I’ll go upstream,’ Thomas says, and is gone for so long that Katherine thinks something has happened to him. He returns in the dark, having got lost in the woods.

‘I like this place,’ he says.

The next morning they are up at cockcrow, loading the boat to the faint sound of plainchant from the abbey. Owen is back at the aft rail again, looking anxious.

‘For all that’s holy!’ Walter cries. ‘No one can’ve followed us here.’

‘Why not?’ Katherine asks.

Walter opens his mouth to say something harsh, but then closes it, looks aside.

‘It’s that Welsh bastard,’ he mutters. ‘He should go and sit at the front of the bloody boat; least that way we’d be able to have a kip.’

But all through the morning Walter keeps glancing back along the length of the river. At one point he frowns.

‘That sail there,’ he says, pointing to a green square in the distance. ‘Seen it before?’

‘Owen says it’s been with us since Stratford,’ Katherine says, but no one replies.

They are in the city of Gloucester by midday.

‘Straight on down to Bris’el now,’ the captain tells them.

The green-sailed ship is still with them, five or six bowshots’ distance, never farther, never nearer.

Katherine is still not sure.

‘Master,’ she asks at last. ‘Do you know most of the ships on the river? What do you make of that one?’

He stares back the boat, the winter sun catching on the bristles of his chin, as on snow.

‘Seen her before,’ he mutters. ‘From Stratford way. Can’t think what’m be doing down this way, though, ’less she’s taking some men somewhere in a rush?’ He looks straight at her and she turns away.

At Bristol they hug the eastern shore of the river as her two banks part, and they sail towards the setting sun until they swing into the mouth of another river and use the tide to take them up between some towering red stone cliffs. A while later they enter the reach under another battlemented castle where the dockside is filled with boats, more than they’ve ever seen in Boston or even Calais perhaps; some seem large enough to carry a church. The houses around them smack of the sort of wealth that only comes through the buying and selling of wool.

‘Come on, come on,’ the boatman calls as they unload the horses, ‘don’t want to be here when the tide runs out.’