Writing a joint novel – even with your best mate – can be challenging. And that’s putting it politely.

There were times when we had really serious disagreements about key elements of the work. We’d almost come to blows over a particular scene in Ice King. But we’d also written other stuff – both fiction and non-fiction – together, including a piece of nonsense called Fantastic People, which was really just an excuse for putting a rag-tag collection of SF and fantasy art into a large and rather expensive book. We solved the problem by inventing the ‘Bremen Transcript’, a newly discovered manuscript describing a raft of unlikely creatures in late medieval pseudo-scientific terms. We were well paid for it, largely because Mike, sensing trouble, used his lawyer’s training to write a suitably threatening letter. Just before the publishers went bankrupt…

We’d also written a history book – The Hammer and the Cross – describing the Viking conversion to Christianity (with a foreword by Magnus Magnusson, whom I’d had the pleasure of meeting on a visit to Iceland when I was 18). And we’d collaborated on computer books for Granada Publishing, which I’ve written about elsewhere.

We hadn’t really expected to collaborate again – until we got an offer we didn’t want to refuse.

The excellent John Jarrold approached us with a request from Games Workshop, creators of the Warhammer game. Would we like to write a novel set in the medieval part of the Warhammer world?

Yes, we decided, we would. And began drafting a story.

Both of us, to be honest, were a little uncomfortable with the Warhammer world, mainly because – for us – it broke a cardinal rule we’d both adopted in writing fantasy. In all our work – separately and together – we’d always gone back to original mythological sources for our ideas. Mike had turned the legend of Wayland Smith – Volundr in Norse mythology – into an epic series called The Winter of the World. We’d drawn on Viking folklore – and our own knowledge of Viking history – for Ice King. And in Dragon I’d gone back to the Danish legends of Hrolf Kraki and Bodvar Bjarki.

Warhammer, to our mind, used fantasy tropes effectively borrowed from Tolkien. Nonetheless, we produced a storyline they found acceptable and moved on to negotiating a contract.

And that’s when things fell apart…

Naively – as it turned out – we asked if we’d get anything by way of royalties for any figures they produced based on our story. Not realising that Games Workshop are almost pathologically unwilling to share such things with anyone. Let alone two lowly authors…

So the deal died. But the story didn’t. Because John came back. How would we like to write the story anyway? But without the Warhammer references?

Thank you, John, we’d like that very much…!

Our story – eventually titled Spell of Empire: The Horns of Tartarus – was aimed squarely at the teenage market, so our young hero, Volker, had the usual awkward relationship with our heroine, Dani. The inevitable sidekicks were Thorgrim Alfvinnsson, a hairy Northerner with two left feet (the type who swings dramatically on a chandelier – and falls off) and a blustering Burgundian named Guy de Guillac, an inordinately powerful magician (but only when drunk). It doesn’t take a lot to realise that these are our affectionate caricatures of each other. In fact one motivating force in the writing – we took alternate chapters – was to land our oppo in as sticky a situation as possible at chapter end so he’d have to write himself out of it in the next…

Background wise we adopted an alternate line of history where the seat of the later Roman Empire had moved from Byzantium to Syracuse (which did, in fact, very nearly happen). This created a Southern Tyrrhenian Empire, focused on the Mediterranean, and left space for a Northern, Nibelung Empire north of the Alps. Italy has become a waste land…

Our ‘magic’ – and many of our ‘creatures’ – were based on classical Greek and Roman mythology, and Volker’s magic, in particular, depended on music, which I played and sang (a lot) and Mike was supremely knowledgeable about. Our heroes’ journey took them south from the Nibelung Empire, across the Alps (thanks to a network of canals, lifts and tunnels created by kobolds, our equivalent of dwarves), down through the dangerous wastes of Italy, to a dramatic and (literally) explosive finale in Sicily. Much later I noticed Terry Pratchett introducing a series of dwarf-built canals, lifts and tunnels in his later Discworld novels. I didn’t steal from him (promise!) but if he borrowed from me I’d take it as a compliment. (More likely it was just two people with the same idea!)

The manuscript was finished and signed off. We were about to get paid. And then disaster struck…