He's currently preparing for his hugely anticipated performance as Hamlet.

But on Tuesday night Benedict Cumberbatch took a break from treading the boards to sit in the audience, heading to London's Trafalgar Studios to watch his Sherlock co-star Louise Brealey in her new play Constellations.

The 38-year-old actor, who welcomed his first child with wife Sophie Hunter last month, dressed down for the production's press night as he dashed through a crowd of fans to take his seat.

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VIP in the house: Benedict Cumberbatch was spotted arriving for the press night of London play Constellations on Tuesday, which features his Sherlock co-star Louise Brealey

Benedict was casual in a t-shirt and navy blue coat as he arrived at the London theatre.

A pair of white trainers finished off the actor's look as he carried a large bag inside.

The star was showing his support for his pal and Sherlock co-star Louise, who plays Molly in the hit BBC1 detective drama.

The talented actress appears opposite Happy Valley's Joe Armstrong in the play from English playwright Nick Payne which explores 'free will and friendship.'

Showing his support: The actor, who welcomed his son five weeks ago, was dressed down as he made his way inside Trafalgar Studios

Night off: Benedict is currently prepping for his anticipated production of Hamlet across town at London's Barbican theatre

The play follows theoretical physicist Marianne (Brealey) and beekeeper Roland (Armstrong), who meet at a barbecue and fall in love.

Each of their scenes repeat themselves, resulting in different outcomes for the couple.

The Royal Court Theatre’s production originally ran at the Duke of York’s Theatre in 2012 with Rafe Spall and Sally Hawkins in the lead roles, and ahead of its return to London the play was touring the UK. The Trafalgar Studios production runs until August 1.

Friends: Benedict's Sherlock co-star Louise Brealey, who plays Molly in the hit BBC show, stars in Constellations, a play from English writer Nick Payne

A Broadway transfer of the play ran earlier this year, with Jake Gyllenhaal making his Broadway debut in the production opposite Ruth Wilson, who received a Tony Award nomination.

Benedict meanwhile will star in the Barbican's production of Hamlet from next month, with the star currently busy with rehearsals.

His prep work meant the actor had to miss last week's Comic-Con event in California, where the Christmas special of Sherlock was teased by the show's co-creator Steven Moffat.

Had a good time?The actor was seen leaving the theatre later on that evening on his own

Specsy! He balanced his glasses on the collar of his T-shirt as he made his way down the street

Arm candy: He carried an oversized brown leather holdall and a pink paper bag from shop, Ark

As well as his theatre work, Benedict has also been kept busy with his new arrival after his wife Sophie gave birth to their son five weeks ago.

The new parents were spotted enjoying some much-needed downtime as they put on an affectionate display at Wimbledon last week.

The couple welcomed their son at the beginning of June, just days after Cumberbatch was awarded a CBE in the Queen's Birthday Honours List for services to the performing arts and charity.

A spokesman for the couple, who wed earlier this year, said: 'Benedict Cumberbatch and Sophie Hunter are delighted to announce the arrival of their beautiful son.'

Keeping it real: The star was casually dressed as he flagged down a black taxi and jumped in