Droll but deadly Arnie

In the beginning, James Cameron had taken The Terminator from its origins as a sensational, violent, science-fiction pulp noir to an operatically philosophical study of the relationship between Man and Machine in Terminator 2. Where else was there for Terminator 3 director Jonathan Mostow to go? The answer is - appropriately for a film that messes with the future - backwards.

He opens with a series of striking images; a riverbed carpeted with skulls, a nuclear missile hammering into the planet, an army of stainless-steel skeletons trampling on humanity. Reluctant messiah John Connor (Nick Stahl) brings us up to date by recapping on the first two movies, remembering his dead mother and declaring the need for living his life on the run and "off the grid", even though he appears to be only dimly aware of his destiny.

Sure enough, his nemesis arrives from the future in the comely shape of a naked female Terminator (Kristanna Loken), who pops up in a shop-store window, melting the mannequins she so closely resembles. Before long she has a car, clothes, a gun and - after scanning a Victoria's Secret poster - a larger embonpoint.

Cosmetic breast enhancement without surgery is just one of the mischievous fantasies embedded here in the margins.

Mostow's serviceable film plunders much of T2's script and relationship dynamics while returning to the sci-fi schlock of the first Terminator, and rings to the clash of metal and crunch of bone.

The plus points are the humour - balanced on a razor's edge between knowing send-up and sentimental self-reference - and the courage of the film-maker in delivering a movie whose theme is unremittingly bleak.

As the Babe Terminator begins to work through her hit-list, Connor establishes his credentials as the saviour of mankind by crashing his motorbike rather than hit a baby deer. Breaking into a veterinary practice in search of painkillers, he gobbles animal phenobarbitol and is found by the local vet Kate Brewster (Clare Danes), who locks him in a cage - not the best place to be when Lady Terminator arrives and starts wasting folk. Luckily, Old Terminator Arnie arrives and rescues the two young people, who are fated to be together.

From then on it's a series of set pieces clustered around a "plot" involving Brewster's father who, it transpires, is the man behind SkyNet - the computer network responsible for the War of the Machines that threatened mankind.

During a rare moment of repose, Arnie the Obsolete Android explains that he is not the same cyber creature who adopted Connor in Terminator 2, but another one who has been programmed by Brewster to protect him. This, of course, was in the future. I frankly confess that I lost track of that conversation about a third of the way in. It didn't seem to matter much.

Terminator 3 is certainly a poorer cousin to the first two movies, but it would be a mistake to write it off. There are many fleeting pleasures and Schwarzenegger has buffed up well not only physically but also in the delivery of the one-liners. When Brewster tells him to drop dead he ripostes with 'droid drollery: "I am unable to comply."