UNSURPISINGLY, given its title, loneliness is the key theme running throughout Frantic Assembly’s I Think We Are Alone, a production celebrating the physical-theatre group’s 25th anniversary.

And it’s a relentlessly mean and depressing world which is its focus. Cabbie Graham is dealing with the news that his wife Bex is dying of cancer while Josie, struggling to mourn the loss of her dad and her beloved dog Queenie, is desperately missing her son Manny — one of the few state-educated black students studying at Cambridge University.

Estranged sisters Clare and Ange can’t bring themselves to talk to each other because they’re both hiding the same dark and disturbing secret about their past which, despite their efforts, they can’t suppress.

Although these characters’ lives each differ in many ways, they’re all consumed by the same fear — isolation.

Co-directors Kathy Burke and Scott Graham spin Sally Abbott’s tragicomedy into a determinedly physical production, with the monologues punctuated by elegant choreography.

Swivelling perspex box partitions are pushed around stage by the cast, representing the suffocating walls which literally close in on the characters — particularly Clare, who believes she stayed in a haunted house when she was a little girl and that the ghosts have never left her side.

Paul Keogan’s bright white lighting creates a clinical and oppressive atmosphere, injected with bursts of colour, as madness or hysteria takes a sudden hold of the characters.

At over two hours, it’s a tad long and the play’s resolution feels rushed, leaving an outcome that seems all too neat and forced.

Yet this is a well-cast production, particularly Chizzy Akudolu, whose Josie provides some much-needed sarky humour in an otherwise sombre, albeit warm-hearted, play.  

Runs until March 21, box office: stratfordeast.com, then tours until May 16.