Sadie died yesterday and, in the Jewish tradition, was buried this morning. Her husband Mordecai, a lapsed Jew, their son Ben, an atheist, and a trainee rabbi gather at the family home to remember her in the tradition of sitting Shivah.

Shiver is the new play by Daniel Kanaber, which opens at the Palace Theatre in February, and acclaimed actor David Horovitch, who plays Mordecai, says it’s his favourite play so far.

“But I do tend to like the last thing I did best,” he laughs. “I did Hysteria at the Hampstead Theatre and I loved that, and I’m sure I’ll look back at Shiver in the same way.”

It’s a play not about Judaism but about families, identities and love – and grief.

“It’s about what grief does to a family,” says David, 68. “Mordecai hasn’t been a practising Jew for years, and neither had his wife, but when she dies he wants to observe the tradition of sitting Shivah – not working for seven days, not going out, not cooking or shaving.

“It’s a sort of comedy of manners, because Mordecai really doesn’t know what you’re supposed to do. I think grief is such a surreal experience, nothing prepares you for it and you don’t know how to grieve. I can remember when I lost someone very close to me, and I said ‘I don’t know how to do this’.”

Mordecai enlists the help of a young, trainee Hasidic rabbi – “not the most competent person in the world” – but son Ben is opposed to the whole idea of sitting Shivah, feeling it’s not what his mother would have wanted. Meanwhile, the rabbi is hoping to lure Mordecai back into the fold.

“There’s this odd kind of triangle between the three characters,” David, who lives in Highgate, explains. “There’s a sort of father-son relationship between Mordecai and the rabbi, who are neighbours and have known each other since the rabbi was a boy, and then between the father and his actual son.

“The play perfectly encapsulates the experience of grief, the ups and downs of it – the sudden feelings of elation that make you feel guilty, it’s so wonderfully written.”

David’s father was Jewish but atheist and married a non-Jew, and David was not brought up in the faith. It wasn’t until he was in his 40s, when he was given a string of Jewish roles, that he started learning anything about the religion.

“People are very surprised when they hear that I’m not,” David laughs, “I think it’s partly my name. I was with Antony Sher in Hysteria and he couldn’t believe it, he said ‘You’re a complete fraud!’”

David ‘became an actor’ at the age of six, when he played ‘the priest all shaven and shorn’ in a school production of The House that Jack Built, and, after leaving St Christopher’s boarding school in Letchworth Garden City, went to the Central School of Speech and Drama in London and, from there, ‘into rep’, firstly at Cheltenham and then Newcastle, before joining the Royal Exchange in Manchester and having a stint in the West End.

He then branched out into television – he’s appeared in Agatha Christie’s Miss Marple as Inspector Slack, Casualty, The New Avengers, and Drop the Dead Donkey – before moving mainly back into theatre, his true love.

It’s been at least 20 years since David was last in Watford – he performed with Helen Mirren in Madame Bovary “oh, at least 20 years ago”, and in Ibsen’s Ghosts and Graham Green’s The Complacent Lover.

“It’s been a long while,” he says. “I was last here when Lou Stein was in charge at the Palace. I walk up the high street every day and have a coffee before rehearsals. It’s nice to be back.”