Suffice it to say that Odin was more than a little concerned about this; and although so far neither tribe had managed to reach the Sky Citadel, their numbers were growing alarmingly. The warriors of Asgard – Thor, Týr and Frey – had made short work of the rock-slinging engines of the Rock Folk, but the enemy had not withdrawn as far as we had expected. Instead they remained around Ironwood, mostly hidden from our eyes, which made the Old Man all the more cautious. The perfect time of crisis, in fact, for me to show my value to the gods. All I needed was the right opportunity.

This finally came when Heimdall – who, by token of his keen vision, had appointed himself Watchman for the rest of us – saw a figure on horseback slowly approaching Asgard. The Ice Folk never used horses – horses don’t thrive in the far North. The Rock Folk did, but not often, and besides, the lone rider didn’t look as if he was trying to stage an attack. He was too slow, to start with. Dressed like a rustic from the Lowlands, he was both unarmed and unburdened; his signature showed no trace of glam, and he approached us openly across the plain, without any apparent concern.

This plain was called Ida, and in those days was a barren, arid wasteland, scattered with the fragments of Asgard’s war defences, levelled during the conflict between the Aesir and Vanir. No one crossed it without intent – usually malevolent – and the gods all watched with suspicion as the rider neared the Rainbow Bridge.

Thor was all for hitting first and asking questions afterwards.

Týr, who was even less subtle than Thor, was of the opinion that hitting first, and then hitting some more afterwards, was probably the best way to go.

Heimdall thought it might be a trap, and that the stranger might be hiding a powerful glam behind his humble appearance.

Balder, who always tried to believe the best in everyone – until proved wrong, at which point he would look pained, as if he’d been personally betrayed – said he thought the man might be delivering a message of peace from our enemies.

Odin gave no opinion. He simply glanced at me briefly, then gestured at Heimdall to let the man pass. Twenty minutes later, the stranger was standing before Odin’s high seat, with all the gods around him.

Closer inspection revealed him to be a broad-shouldered man with iron-grey hair, as slow and massive as his horse. He wouldn’t give his name. Nothing surprising about that – names, like runes, are full of power. Instead he looked around at the hall – which was solidly built from ancient oak – then around at all of us. It was clear he wasn’t impressed.