I tracked Thiassi back to his stronghold – the Ice Folk are careless with signatures – a castle built into the rock in the cleft between two mountains. It was bleak and very cold – even with Freyja’s feather cloak I was half frozen in the air – but luck was on my side, because I found Idun almost at once; alone and shivering by the fire in one of the castle’s many rooms.

I stepped out of the feather cloak.

‘Loki!’ she cried, and hugged me. ‘I knew you’d come to rescue me!’

I said, ‘Where’s Thiassi?’

‘Gone ice-fishing with his daughter, Skadi. I don’t like her,’ Idun said.

I thought that if Idun didn’t like her – Idun, who thinks that wolves and bears are cute and that even Your Humble Narrator has a soft side – then Skadi must be something else. I made a mental note to avoid her.

‘All right,’ I said. ‘Then let’s go.’

A single cantrip and I’d changed her into something a falcon could carry. Then I swept her basket of apples underneath my falcon cloak and let it transform me once again. A moment later, we were off; a falcon, flying hard and high, carrying a hazelnut.

This time, I wasted none of my glam trying to go unseen, but simply concentrated on speed. How long before Thiassi and Skadi returned? How long would it be before Idun was missed?

I knew that Thiassi’s eagle form was more than a match for a falcon. I was fast, but he was faster, which meant that even with a head start, I could expect him to catch up with me long before we reached Asgard. In fact, I was three-quarters of the way there when I saw the speck in the sky, hunting me, observing me.

I waited until he was close enough, then shot him with the rune Hagall. The eagle dropped back for a mile or so, then started to creep back again. I gave him the fire-rune Kaen as I fled, and folded my wings to increase my speed. Thiassi tracked me for an hour that way, keeping his distance, but close enough to move in for the kill as soon as I showed any weakness. I was getting tired by then, and my glam was weakening. I gave him a blast of the rune Thuris and felt myself flagging in mid-air; Thiassi saw it at once and began to circle me from above.

But I could see Asgard, ten miles away, shining and gold in the sunset. If only I could reach it in time. Ten miles . . .

‘Hold tight,’ I said to Idun in her hazelnut form. Then I increased my speed again, leaving nothing in reserve. The seconds passed. The hunter drew close. By the time I’d reached the Rainbow Bridge, I could actually feel him on my tail.