Daphne du Maurier's best novels are like multi-faceted diamonds: different lights transform them. The light of the reader's perspective, that is. I was pretty much marked for life when I saw Hitchcock's Rebecca (1940) as a child, particularly when my mother intoned the opening line: “Last night I dreamed I went to Manderley again.” But I took the Gothic romance at face value. Reading it a couple of years ago I was stunned by its complex anti-imperialist, feminist narrative told by a gloriously flawed narrator. It's a great mystery thriller, alright, but it is the reader's own romantic assumptions which are most questioned.

My Cousin Rachel (1951) does the same thing differently. It is another anti-imperialist, feminist narrative told by another flawed narrator, this time a man: Philip Ashley. He is a young man born of man alone, in a sense. His mother died when he was a baby. His uncle Ambrose “sent his nurse packing” and raised the child himself. The Cornwall estate is run entirely by men for men who go every Sunday to a church (Anglican) which has no Madonnas. It is sterile ground.

Until Rachel arrives. Beautiful. Italian. Catholic. The good old British status-quo struggles to reassert itself. And does, of course, in the end.

We can never decide if Rachel is a malign or a benign influence, because du Maurier plays mercilessly with our preconceptions. And so a pacy plot is born. Rachel, Delilah or Madonna, has married Philip's uncle Ambrose in Florence and he has mysteriously died. His nephew is flipping mad. Until he sees the widowed Rachel and falls in love for the first time.

Will they live happily ever after? Will Rachel destroy him? Or he her?

Joseph O'Connor has carefully lifted the bare plot out of the novel and written it with all its twists and turns, so the audience is actually gasping. It's wonderfully entertaining. He has ignored the deeper critique of misogyny in the novel – along with the fact that Rachel lost Ambrose's baby and can have no more – in favour of a more traditional feminist message. Rachel is economically dependent on men. All she has to sell are her charms because the Ashley estate does not think it proper that she should work for a living.

This message works well, even if it is not du Maurier's. However in some ways this production, directed by Toby Frow, sells du Maurier short. Literally so, in the casting of Michael Legge as Philip Ashley. Philip's height is stressed in the novel and it works well as a way of eroticising the relationship between him and his uncle's widow. Michael Legge does not look like a match for Hannah Yelland's Rachel. Nor does he achieve enough depth as a character, particularly in the wooden opening scenes, in which there are far too many moody glances into the middle distance.

By contrast Yelland is very strong as Rachel, reassuringly domestic and tough as nails. O'Connor's script allows her to exploit the incredible dramatic highpoints of du Maurier's story, which had the audience on the edge of its collective seat. Bryan Murray strikes a new note in his career in his creation of the sinister Italian solicitor Rainaldi who comes sniffing after Rachel or her money or both.

But this is essentially a traditional production of a period mystery story. The Gate has a formula for its literary adaptations, which feature strong ensemble playing, and this show is no exception. Bosco Hogan is wonderful as the faithful old retainer, Seecombe, but it was John Cronin as the lame Thomas Connors, an O'Connor invention, who was the performer of the night. I was powerfully aware at all times that the collapse of the estate would leave him hobbling down the road to penury.

Francis O'Connor's set and costume design are very beautiful traditional period creations, particularly Rachel's magnificent mourning. Denis Clohessy's soundscapes blend menace with mandolin to evoke danger from a place as hot and seductive as the widow. Mark Jonathan's natural light streams through the high windows of the great estate, facing the sea.

It is at the end, in the sea scene, that O'Connor's script's relationship with its mother novel falls asunder. O'Connor sets his play in a mythic Cornwall and connects Rachel to the ill-fated Queen Guinevere who is unfaithful to King Arthur and brings about the collapse of his kingdom, or is torn to death, or both. There is a sense, in the end, that Rachel, like Guinevere, has been defeated by ancient mythic forces which well up like the sea to claim her.

This works well until you see how much better the novel ends. In it there is no recourse to myth, just to psychology. It is Rachel's bourgeois ambition to bring beauty and fertility to the wild estate which causes her to over-reach herself. And she is defeated, in the end, by nothing more than Philip's appalling misogyny. The British estate, with its sterile centuries of history, has its revenge; not the stormy waters.

But the main issue with O'Connor's ending is that it doesn't work dramatically. What we are left with, in the end, is a visual image of Rachel – but it is not enough. There are too many questions. There is no narrative voice, as there is in the novel – or as there was indeed in Conor Mc Pherson's adapation of du Maurier's The Birds for the Gate (2009) – to tie the story up by reflecting on Philip as the villain of the piece. If the voice of a narrator were to be avoided, another scene projecting Philip into the future as the guilty survivor was perhaps needed.

Though the ending was abrupt, it didn't seem to dent the enthusiasm of the audience, however, who had enjoyed a constantly engaging and hugely enjoyable evening of theatre.

Victoria White