His Dark Materials (BBC1, 8pm) ****

OF the many mysteries spun by Philip Pullman’s fantasy epic, one looms large. Why, despite shifting phenomenal amounts in novel form, some 18 million sold to date, and being a relative success on stage, has His Dark Materials never lit up the screen successfully?

Some £140 million was spent on a 2007, all bells and whistles movie which, praise for armoured polar bears and Nicole Kidman aside, failed to fly. Now the BBC and HBO have splashed a rumoured £50 million on an eight part adaptation for television.

Worth it? While first impressions were favourable, that is still a lot of money. One and a half new BBC Scotland channels to be precise, or 323,624 licence fees for over 75s.

Jack Thorne, the writer of Shameless and Harry Potter and the Cursed Child, was in charge of the adaptation. He gave little quarter to anyone unfamiliar with the novels. After a brief introduction covering the all-powerful ruling elite, known as the Magisterium, and a prophecy about a special child, we were pitched into a world very much like this world, yet somehow not. Welcome to the endless strangeness and complexities of Pullman’s universe.

Previous adaptations have fallen down in trying to get across the trilogy’s many and complex themes too soon. Wisely, this production homed in instead on the “daemons”, the spirit animals that encapsulate the souls of the humans to which they are attached. Scientist and explorer Lord Asriel (James McAvoy, one of several Scots in the cast including James Cosmo and Gary Lewis) has a very cool snow leopard as his daemon. His orphaned niece, Lyra, the child on whom so much will depend, has a stoat. Who doesn’t love a super furry animal that can talk?

British-Spanish actress Dafne Keen is excellent as the fearless, inquisitive Lyra, her dark features calling to mind the heroine of Pan’s Labyrinth. McAvoy makes an awesome adventurer, never happier than when there is a swash to be buckled.

Asriel has just blown in from the frozen north with tales of a mysterious substance he calls “dust”. The existence of this material, which appears to conceal other worlds, is contrary to the Magisterium’s teachings. It is the kind of information, indeed, that could topple empires.

The mentions of “dust” had unfortunate comic echoes of the Little Britain sketch about a slimming group leader who tells members that dust is all they can eat if they want to lose weight. The daemons, for all they were delightful in the main, took a while to get used to. When we could see their lips move it was obvious they were talking; when we could not, their seemingly disembodied voices only added to the mounting confusion.

Just when the story showed signs of slipping away, something happened that bodes well for any television drama: Ruth Wilson rocked up to play the mesmerising and beautiful Mrs Coulter. Offering Lyra a job and the chance to move to London, the character played by the star of Luther and The Affair seems a dream come true for motherless Lyra. But her daemon is a gorgeous but terrifying golden monkey - so make of that business what you will.

By episode end, Asriel was racing back to the North, and scores of others were heading to London in search of vanished children. With armoured polar bears and Lin-Manuel Miranda (Hamilton) still to come, it would be a brave soul indeed who bailed on His Dark Materials this early. Keep the faith.

Available on iPlayer