Where the first half of Journey was primarily scene setting, before the roller-coaster second half, Desolation opens with a rapid-fire series of set-pieces before ultimately slowing to a more affecting film. Sadly, most of the opening set-pieces just feel like box-ticking – here’s Beorn, here are the (admittedly frightening) spiders, here are some wood elves, etc – before the real film blooms in Lake-town. Here, the action slows, and the film allows its world and its characters to breathe, and as the cast are split between Lake-town and those delving into the mountain lair of the dragon, Desolation comes alive.

The cast swells in this middle instalment, with Evangeline Lily making a welcome addition as spirited wood-elf Tauriel. Her unlikely romance with Kili (Aiden Turner, still the most rounded of the dwarves – Bombur aside) is well drawn, and despite their minimal screen-time together, their connection is well-sold… none of which goes down particularly well with Legolas (Orlando Bloom, returning for more Middle Earth action).

Legolas is a fan favourite, but here he’s turned into some sort of boringly invincible orc-killing machine. He’s so incredibly adept at killing orcs that it becomes uninteresting. Where Gandalf was the dues ex machine that rescued the gang from every scrape in the first film, here it’s Legolas and his bow. He’s too awesome, and it just begins to feel like fan-service. In fact, with Azog the Defiler taking a step-back, the orcs in general are reduced to mere blade-fodder.

The other main addition is Luke Evans as Lake-town resident Bard the Bowman. Evans is a good fit for the roguish smuggler with a weighty family history; Bard and his family place a necessary human face on proceedings – quite literally.

Ian McKellen is classy as ever, even as Gandalf’s thread here is a tad superfluous; Stephen Fry has fun as the drunken Master of Lake-town; while Richard Armitage as Thorin Oakenshield, leader of the dwarves, continues to be a good leader and lead. And Martin Freeman simply is Bilbo Baggins.

And then there’s Smaug.

Wow. One of the main selling points of filming The Hobbit was surely to bring the dragon to the screen, and if he was only teased in the first instalment, my word, was he worth the wait. Gollum was a game-changer in terms of CGI characters as characters, and if the game has changed, Smaug might just have won it.

Smaug is huge in a way that the Kaiju of Pacific Rim can only dream of. He fills the screen and dominates the film. As the voice of the great lizard, Benedict Cumberbatch – already reptilian enough – excels. His distinctive, cold, enunciated croon is wonderful.

In the very truest tradition of Hollywood blockbusters, Smaug provides a sense of spectacle; his titanic presence adds heft and weight to proceedings that the abstract threat of the Necromancer just cannot provide. For that matter, why bother spending so much time on Sauron’s imminent return when we’ve got Smaug? Never-mind a disembodied eye; here is a real villain.

There’s no doubt that the film – and franchise – comes alive with Smaug’s introduction, and if what comes before it is uneven, there are still moments of fun to be had. A river chase, with the dwarves bobbing along in barrels, being chased by orcs, is perhaps the most purely entertaining sequence in the franchise – one gleefully virtuoso shot in particular is Peter Jackson at his tongue-in-cheek best. Sadly, while Smaug is flawless, the CGI elsewhere – particularly in the aforementioned river chase – is at times rather too video-gamey to entirely convince.

The Desolation of Smaug is, like its predecessor, imperfect, but a lot of fun. The Hobbit franchise is still not on the same level as The Lord of the Rings, but the latter half of Desolation certainly elevates it a lot closer.

The Hobbit was always going to live and die by the strength of its dragon, and Smaug is stronger than we ever could have hoped – a stunning achievement. And with the breathtaking climax leaving things precariously, thrillingly balanced, despite the lengthy run-time, Desolation will leave you wanting more.

Released in UK cinemas on Friday 13 December 2013.

> Buy The Hobbit: An Unexpected Journey on Blu-ray on Amazon.

> Buy the Lord of the Rings trilogy boxset on Amazon.

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