"What attracted me was definitely the combination of cast and crew," says Lau when we meet on the day of 's first rehearsal session in late May. "I've been wanting to return to the stage for several years now. A few theatre directors have approached me with projects over the years, but perhaps it's fate that I agreed to this one. I took up this opportunity without hesitation - there wasn't even a script when I accepted."

The actress' last theatrical turn was for the musical , which ran for 64 performances from November 2000 to January 2001 at the Lyric Theatre at the Academy for Performing Arts, the venue for . It may feel like déjà vu for the production team: both and are produced by Albert Yeung Sau-shing of Emperor Entertainment Group. They share the same director in Fredric Mao Chun-fai, and stars in Carina Lau and Tony Leung. Even Gardner Tse was assistant director for the earlier work.The concept of was conceived by producer Vicky Leung Lee Siu-ha, who is the director and treasurer of the Hong Kong Motion Picture Industry Association. She was an influential industry figure during the Hong Kong New Wave cinema movement of the 1970s and '80s.

Having accompanied her husband to Tonnochy several times in the '70s she briefly became friends with some of the hostesses, whom she describes as "carefully selected and reasonably educated". Leung says the nightclub was a symbol of luxury and decadence amid the hardship that the general public endured during that era. "Everyone visiting Tonnochy had a story," she says.

The script was written by Candice Chong Mui-ngam and further enhanced by William Chang Suk-ping's art direction and costume design. 's plot involves a trio of characters at the club: Tse's audacious stock market player, Tony Leung's introverted banker and Lau's widow, who comes looking for answers following the mysterious death of her husband.

With its 11 actors and 15 chorus members, the play is a complicated web of fraud and romance among a group of businessmen and hostesses at the nightclub. Tse says: "Every character is living in a beautiful dream. They all realise that but are unwilling to wake up from it. This is about their attempt to enjoy themselves while it lasts."

represents the third time that Leung has worked with director Mao. The actor says he was most inspired by a chat he had with Tse during the production of . "I remember Tse telling me back then: 'when we make films, the actors are in a passive position because everything is eventually in the hands of others. But when you do theatre, no matter what happens during the rehearsals or how controlling the director is, when the curtains part, the stage is all yours'."

Tse calls Tonnochy "a very special play" in that "it's very refreshing for me because I've never done a play set in the 1970s", he says.

Although the Hong Kong theatre scene is thriving nowadays, Leung believes there is a need for a greater variety of original works that speak to the city's local history. "The fact that this play is set in Tonnochy puts a strong emphasis on its historical context," Leung says. "Tonnochy is a symbol of so many things from that time, including the blooming economy, [and the contrast between] the richest and poorest members of the population … "

"The essence of that era," Lau chimes in.

"The play provides a microcosm of society at that time," says Leung. "I hope that this will become a classic in the Hong Kong theatre scene. I hope people will return to it and restage it every year, so that this can become a representative play that is passed on through the generations. We have a great sense of purpose."

"Whoa," Lau says, laughing, "what a great sense of purpose."