This is a story about courage. A troupe of circus performers goes on a crime spree when they accidentally acquire superhuman powers (and possibly undergo some kind of mutation). However, one of them, an ordinary clown, does not agree with their misdeeds. For the goodwill of the city, he declares a battle on them. Aaron Kwok plays the clown, with Shu Qi as his love interest.

Hong Kong director Benny Chan says his upcoming film will feature stunning special effects that are in line with those in "X-Men Origins: Wolverine".

"It's basically China's answer to 'Wolverine'," Chan told reporters at a press conference in Hong Kong on Wednesday, where he was leading cast members to promote his sci-fi action film, "City under Siege".

The director says computer-generated scenes are likely to occupy half of the film.

"City under Siege" revolves around a circus clown and his colleagues who experience physical changes after accidentally ingesting a biological gas.