"There's a line in it - 'There's a great deal of pain in the world, Mrs Manningham' - I think that was the same in 1938 and in 1880 when it was set and now ... when people are trying to manipulate each other."

Her character, Bella, was disowned by her family after she married Jack Manningham (played by Peter Holland). The couple now live in a house in Angel Street where Bella is a virtual prisoner, manipulated by her husband until she doubts her own sanity. But why is he doing this? And why does the gaslight in the house go down when he mysteriously disappears at night?

Gaslight was last produced by Rep in 1946 and Blackhurst said that while it was old-fashioned in some ways in others it was still relevant because many people still find themselves in abusive, manipulative relationships. She said the term "gaslighting" for a particular kind of mental abuse that involved making someone doubt their own sanity entered the language from this play.

And, she said, Bella was more than just a victim.

"We see what she might have been like before her marriage ... she still has an incredible inner strength."

Holland is better known for comic roles but said he was enjoying the opportunity to play "a manipulative, scheming, lying, charmer ... the classic psychologically abusive husband".

The challenge, he said, was to combine charm with cruelty and make it convincing rather than camp it up.

Blackhurst and Holland have worked together several times, including in Rep's Twelfth Night, and Blackhurst said they were nothing like their characters in Gaslight.

"I hope he's a lot nicer and I'm a lot less mental than I appear!"

Gaslight is on at Theatre 3, Ellery Crescent, Acton, from July 30 to August 15. Tickets: canberrarep.org.au.