The final act is breathtaking

Film critics can sleep easy in their beds once more. The last tranche of Peter Jackson's marathon celluloid extravaganza has come to a conclusion. No more the dread of the three-hour numb bum, of the relentless special effects, of the tweedly-dee sawn-off heroic hobbits. We are, as it were, released from captivity.

The third and final part is by far the best. The tale begins to make sense, the good end happily and the bad unhappily. That, after all, is what fantasy means.

The plot can dispensed with very quickly. Frodo (Elijah Wood) and Sam (Sean Astin) are still en route to Mount Doom to dump the ring of power and thereby knock out Sauron's power grid. Meanwhile, Gandalf (Ian McKellen) and Aragorn (Viggo Mortensen) are attempting to fight off Sauron's invading Orcs and all manner of beasties. There's a bit of love interest to be concluded between Arwen (Liv Tyler) and Aragorn but that's by the by. As plotlines go, it's pretty slim stuff but I guess we have to lay the blame at JRR Tolkien's door.

Tolkien's fantasy is closely allied to Arthurian legend. For the Fellowship of the Ring read the Round Table; for Sauron read Mordred; for Gandalf read Merlin. And when Frodo is beckoned onto the boat at the end I almost expected Cate Blanchett's Galadriel to say: "Ding dong. Avalon calling."

To cap the first two movies Jackson flings in everything but the kitchen sink. Here be flying dragons, giant trolls, orcs by the multiple CGI-load, a truly terrifying spider and, of course, the great scene stealer, Gollum. It is something extraordinary when a computer creation (albeit voiced and physicalised by the brilliant Andy Serkis) has more depth and nuance than most of the live actors. He is the ultimate slippery, sneaky creep - a cross between ET and Uriah Heep.

The rest is a welter of gobsmacking special effects - great battle scenes of breathtaking scope and invention, extraordinary architecture and design, stunning landscapes. I particularly enjoyed the bowslinging elf Legolas's prowess in bringing down a war mammoth, climbing nimbly up the creature's flanks and swinging like Tarzan from one shooting position to another.

But there is another discreet agenda at work. The most heroic characters of all are either old (Gandalf) or persons of restricted growth (the hobbits). Sam Gamgee, a diminutive fat boy, is the last boy scout. My personal view is that he is a metaphor for director Peter Jackson himself - who resembles a truncated Francis Ford Coppola and who has achieved the impossible in creating the most successful cinematic event movie of all time.