AS any film buff will know, whenever a top secret military lab is working on a deadly new super-virus, some berk is going to accidentally let it out and put the whole of humanity at risk.

And that's the case here at the beginning of Stephen King's epic five hours and 45 minutes film adaptation of his own novel.

As the virus sweeps across America, a small number of people find themselves inexplicably immune to it. Stranger still, the survivors all begin to dream about a 106-year-old woman called Mother Abigail, urging them all to come to her at her home in Nebraska.

But the dreams also contain disturbing visions of a red-eyed demon called Randall Flagg, who has his own band of followers and who is hell-bent on taking over the world.

Flagg is able to appear in human form, and when he does so, he looks rather like a cross between Russ Abbot and Billy Ray Cyrus - which kind of figures, I suppose.

With the survivors splitting into two camps, the story leads to an inevitable showdown between good and evil, with the future of the world at stake.

Remarkably for such a lengthy film, the plot manages to remain interesting throughout, with the long running time allowing King's screenplay to fully flesh out a large number of characters on both sides of the battle.

The production values are adequate rather than great, but to his credit, director Mick Garris focuses more on human emotions rather than million-pound explosions.

A fine ensemble cast includes the always superb Gary Sinise along with Molly Ringwald, Laura San Giacomo, Miguel Ferrer and Rob Lowe, the latter excellent as a deaf-mute.

It's a long haul but stick with it, as this is one heart-warming journey that's well worth making.