Shot with an English-speaking cast in Malta and set in the fourth century in Roman-controlled Alexandria (ancient Egypt to you, pal), “Agora” has everything except real drama.

It stars Rachel Weisz, who can slip in and out of various historical periods without seeming like a stranger. She plays astronomer Hypatia, daughter of Theon (Michael Lonsdale, master of understatement as always), who was final director of the Alexandrian library. Greatest in the world at the time; greatest of all time, some say.

“Agora” is conceived as a historical romance between a woman and her intellectual passions. With Christian unrest swirling around her, this “pagan” astronomer — the prototypical sexy librarian, without the specs — contends with two disparate suitors. One, played by Oscar Isaac, has money and class; the other, Hypatia’s doting slave (Max Minghella), feels the tug not only of dead-end lust, but also of what the film’s production notes refer to as “the unstoppable surge of the Christians.”

To be sure, several good things can be found in “Agora,” among them a welcome discretion in its computer-generated crowds and God’s-eye-view visual effects (we get plenty of both, but less bombastically than usual).

With fire in her eyes and the riddle of the solar system in her brain, Weisz struggles in fleshing out a historical character well worth a movie, though frustratingly sketchy as written here.

Amenabar is well aware of the parallels between the destruction and looting of the Alexandrian library in the film, and the destruction and looting of ancient artifacts in more recent times (see Baghdad, early 21st century). The echo can be heard, and the director was right to intimate the comparison rather than hammer it.

“Agora” nonetheless leaves you with a peculiar sensation of having spent a couple of hours with an epic-worthy woman, played by a superb actress, without really getting to know what made her tick.