Hellboy II is a strange and seductive beast. It’s a wonderful mix of pulp fiction and fairy tale, monster saga and Tolkien mythology. Imagine Philip Marlowe going down the mean streets of an underworld awash with psycho goblins and killer fairies. With this, his sequel to Hellboy (2004), the director Guillermo del Toro has created the most visually sumptuous and entertaining blockbuster we have had all summer. Christopher Nolan, eat your heart out.

Hellboy (Ron Perlman) — that’s his code name, because obviously it’s a lot cooler than his real name, Anung un Rama — is a big, red, muscular demon with a tail, and a right hand that’s like an anvil. He works as a kind of detective for the secret Bureau for Paranormal Research Defence and lives with his girlfriend, Liz (Selma Blair), whose pyrokinetic powers mean she can burst into flames at will. Like many couples, they’re having troubles — Hellboy is a slob around the house — but domestic disputes are pushed aside when duty calls. The ancient truce between humans and magical creatures has broken down. Prince Nuada (Luke Goss) has decided to declare war on mankind and get the earth back for his underworld people. He plans to do this by awaking an ancient Golden Army of invincible killing machines.

One of the most appealing things about del Toro’s movie is that it rejects modern cinema’s tendency towards realism and relevance. (Here, thank the Lord, is a film devoid of any post-9/11 connotations.) What fascinates del Toro is the fantastic. Where so many other directors use imaginary worlds to illuminate our world, he uses our world to illuminate the imaginary. He does it brilliantly. The opening scene, which depicts the battle between humans and underworld creatures with marionette-like wooden figures, is a beautiful evocation of a fairy-tale war that mixes adult horror and childlike innocence.

The reason I suspect his film works so well is that the child in del Toro is still able to believe in fairy tales. Yet his freaky characters are as real as any human. And what a great collection they are: Abe Sapien (Doug Jones), a fish-like “aquatic empath” who falls in love with Nuada’s sister, and Johann Krauss (voiced by Seth MacFarlane), a bossy German who is nothing more than gaseous ectoplasm confined in what looks like one of those old-fashioned diving suits. Likewise, del Toro’s monsters and evil ones are fresh and fascinating. Consider the Tooth Fairies, who are a cross between Tinkerbell and baby piranhas — they devour and excrete their victims in one go.

Strange to say, the one disappointing character is Hellboy himself. Although he was born a demon, and is often referred to as a monster, there’s nothing demonic or monstrous about him. His powers aren’t that exceptional or interesting. He’s just a big lug, a grump with a heart of gold who can hit people really hard. As a fantasy figure, he’s awfully familiar. Ditch the tail and the red skin, and Hellboy is the hard-boiled, wise-cracking cop who breaks the rules, but gets the job done. Here is the hero as regular guy, a man who likes his cigars, beer and watching television. You won’t find a dark side to him, which makes a refreshing change; but you don’t find much else either. So keen has del Toro been to make him an ordinary joe, he ends up ordinary. There’s no depth to this demon. So when he faces the great choice of siding with the humans or the magical creatures, we never doubt for a second which way he will go. I mean, everyone knows you can’t get beer and cigars in the underworld.

There are plenty of big battle sequences for the fan boys, but, instead of playing to adolescent bloodlust all the time, del Toro tries to surprise us. After Hellboy has defeated a giant vine creature in Manhattan, for example, we get a scene of unexpected beauty — the streets are transformed into a green and magical space. It’s a wonderful moment. Even the sword-fighting scenes, which are usually so tedious to watch, have a wonderful snap, pop and crackle to them. For my money, the star of the show is the Prince Nuada character, and here the former Bros star Luke Goss gives a superb, athletic, authentic performance — every bit as good as Heath Ledger, without the crazy mannerisms.

We get a good old story of good v evil, but we also get a romantic tale about falling in love. One of the most comic and poignant scenes is when our two love-struck monsters, Hellboy and Abe, get sloshed on Mexican beer and sing along to Barry Manilow’s Can’t Smile Without You. With Hellboy II, the comic-book blockbuster has finally grown up — without giving up the fairy-tale wonders of our youth.

12A, 120 mins (opens Wednesday)

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010