When his demanding leading lady (Ryder) storms off set, film director Viktor Taransky (Pacino) is facing a place on the film scrapheap.

Fired by a studio exec who also happens to be his ex-wife (Keener), Taransky has to think fast if he's going to salvage his career and resurrect his flailing reputation.

Thankfully, the legacy of an oddball scientist (Elias Koteas) comes into play when Viktor discovers a computer programme that enables him to create a digital actress - a virtual film star, minus the temperament of the human variety.

Viktor's "synthespian", Simone, is soon a star. Adored by audiences, she even releases a single, but Viktor decides to keep her fakeness a secret, winding up in more trouble than she's worth.

From the writer of "The Truman Show", you'd expect some digs at the media industry, and "S1m0ne" sets itself up as a satire of star-worship and the shallowness of modern-day fame.

Simone herself is almost-living proof of how inaccessible modern stars are - nobody's seen her in the flesh, but they don't doubt her existence.

But while the script starts promisingly, it loses steam towards the middle and never really develops beyond attacking obvious targets - tabloid hacks, film studio execs, and sucker fans are all easy prey.

Viktor's relationship with his female alter-ego is the most amusing aspect of the film, with his web of lies slowly spinning out of control.

Driven to his wits' end trying to keep his secret, the bedraggled Pacino is up to his usual husky-voiced histrionics here. But even he fails to make this film as flawlessly realised as its computerised star.