Here is another review from a theatregoer, who saw this play on Wednesday the 21

https://therealchrisparkle.wordpress.com/2015/10/22/review-gaslight-royal-and-derngate-northampton-21st-october-2015/
"... the scenes between Jack and Bella were superb; a really fantastic study of the chilling domination of one person over another....Jonathan Firth is also superb as the calculating and cruel Jack, really using the pace and control of his voice both to dominate and to lull Bella into a false sense of security. It’s a beautifully understated characterisation of evil – it wouldn’t surprise me if he committed any appalling act he wanted....."