There was a moment soon after becoming a father for the first time when Alex Waldmann recalls looking around and thinking "where are the adults?".
It is a question many first-time parents must have posed before quickly answering, as he did, "oh yes, that's us".
The actor, who now has two young daughters, has been drawing on those bewildering early days of parenthood for In the Night Time, at Notting Hill's Gate Theatre - a hallucinatory look at the trials of being a new parent.
He plays 'Man', one of two parents at their wits' end because they cannot get their newborn baby to stop crying.
As despair descends, the planet's darkest horrors come crashing in to the couple's studio flat, leading them to contemplate what it means to bring a new life into such an imperfect world.
"A lot of it's quite familiar territory but Nina (writer Nina Segal) explores that feeling of being a new parent in a way I've never seen before," says Waldmann.
"She captures all the anxiety that comes with having your first child and takes it right to its furthest conclusion."
Being trapped in a small room with a screaming infant is no one's idea of fun but, as Waldmann explains, the play examines the soaring highs as well as the crushing lows a first child brings.
'There's also a joy which nothing can equal'
"When you have a baby there are extremes. You have the worry and the sleepless nights, but there's also joy which nothing can equal," he says.
"There's a lot of humanity and laughter and warmth in Nina's script which makes up for the bad stuff."
Not only is this Segal's first professionally produced play, she wrote it without having children of her own.
Waldmann says he was blown away by her grip on the depths to which the human mind can plunge when you're deprived of sleep and feeling out of your comfort zone.
She also seems to get that nagging sense of guilt which comes with being a new parent, he explains, about whether you could be doing more for the world in which your child is growing up.
"These are two people who watch the news but wonder if by recycling and eating Fair Trade chocolate they're really doing enough," he says.
"When you've brought a child into the world you're always questioning whether you're doing enough. Can you ever really care enough (about the state of the world)?
'It's you against the world'
"I remember in the run-up to having our first baby we stopped watching the news because you don't want to fill your head with all those violent images. You want to be positive.
"You become this tight little unit and it's you against the world. I remember thinking somehow what was happening in the world wasn't so important. All that mattered was this little unit."
If the play's title has the ring of a fairy tale or children's TV programme to it, Waldmann suggests that's no accident.
"It's very much about notion of storytelling. When you really start analysing the classic children's stories, you realise many are quite dark and violent," he says.
"Do you come clean about the way the world really works, warts and all, or do you try to shield your child from some of the horror?"
If that all sounds a bit heavy, at least the choice of bedtime reading matter is a decision parents popping down to the Gate Theatre can leave to the babysitter for one night.
* In The Night Time (Before the Sun Rises) is showing at the Gate Theatre, in Notting Hill, from February 8-27, with previews from February 4.
For tickets, starting at £10, visit the Gate Theatre website or call the box office on 020 7229 0706.
