Harold received them in his chamber, a magnificent stone-walled room at the heart of Edward’s Westmynster palace, with a fireplace so large Godgifu could have walked into it. He was working through papers with clerks and a couple of housecarls, who hastily read through the documents for him and held them up for him to make his cross. Harold’s big warrior’s frame looked restless under the fine garb and, like Sihtric, he looked as if he had had little sleep.

When Sihtric, Orm and Godgifu were shown in, he dismissed his clerks and crossed to a bench where he poured himself a cup of mead. ‘I’m somewhat busy, priest.’

‘I can imagine, lord—’

‘William is moving. Have you heard that? He is trying to raise an army of seven thousand, my spies tell me. He needs the support of his Norman nobles for that. He’s seeking recruits from Brittany and Boulogne. He’s even writing to the damn Pope. He means to invade, that’s the top and bottom of it ... Make your case and make it quickly, Sihtric.’

Sihtric, his tension showing, unrolled a scroll. ‘Behold the Menologium of Isolde. I now understand it fully, lord, so I believe. And, troubled as this time is for you, I believe the Menologium shows you a clear path.’

Harold grunted. ‘My brothers say I should dispose of you. My pet soothsayer. They call you a chancer.’

Sihtric held up the parchment. ‘But this is no fortune-telling, no scrying of entrails. This is scholarship, which—’

Harold waved away a document he couldn’t read. ‘Yes, yes. Just tell me.’

As the name implied, the Menologium was a calendar - a calendar of history. It was structured around the Great Year, the seventy-seven-year return cycle of the comet, which even this month should blaze in England’s skies.

‘But there is no comet,’ Harold pointed out.

‘It will come, sire ...’

Sihtric had been able to interpret the Menologium with the help of the Moorish scholar who had converted Great Years to Christian dates, by matching Menologium dates to histories like Bede’s, and by drawing on studies of the prophecy itself that went back centuries, to Cynewulf and Boniface, long dead.

‘We have a prologue, epilogue and nine stanzas,’ he said. ‘Each stanza spans a Great Year, punctuated by a comet visitation. The first can be dated to Anno Domini 451, when our German forebears first rebelled against the British king who had brought them to England. And later stanzas describe specific events, though cryptically.’ Thus stanza five predicted the coming of the Norse to Lindisfarena. Stanza six foreshadowed Alfred’s first great victory against the Danish Force.

Some of the Menologium’s stanzas seemed to have been inserted to give a historical anchoring to the timeframe, and they were only becoming clear with the passage of time. Sihtric quoted stanza eight: “‘At the hub of the world/Match fastness of rock/against tides of fire” ...’