ANNA, National Theatre ★★★★★

There is a headset hooked onto every seat in the Dorfman Theatre. When you put it on, you hear ‘Left Ear. Right Ear’ until ANNA begins. This diurnal sound, where sounds play into different ears, tricks your senses and exposes every choked breath or strangled whisper that transpires in the taut, tense Cold War thriller.

A pair of headphones is a simple addition to the production, sound designers Ben and Max Ringham immerse you into the playworld and makes you culpable in the twisty tale of spying, surveillance and secrets.

After the successes of Oil in 2016 and The Writer in 2018, rising star playwright Ella Hickson delves into 1960s East Berlin. We follow the titular Anna, played by a nervy Phoebe Fox, as she hosts a party to celebrate her husband Hans’s promotion. As the colleagues and new boss arrive convivial small talk cannot hide an increasingly uneasy atmosphere.

Director Natalie Abrahami and designer Vicki Mortimer keep us uncomfortably close to the drama, while also shutting us out. Set up like an artfully mid-century apartment, the stage is covered with a clear perspex panel: we peer in like voyeurs. Low lighting and blackouts give the spooky sensation that somebody is is hiding in the shadows.

But the sound design takes us inside this apartment. We hear things as Anna. If she leaves the room, we can still see the party in full swing but music and merriment is muffled. We hear retching behind the bathroom door and hushed, hurried confessions to her husband and snatches of conversations as Anna flits between guests.

Without giving away any spoilers, there plot twists come thick and fast. At just one hour it’s slick, quick and a thrill to watch. This speed of dramatic escalation is what keeps you guessing, even it it occasionally overpowers the emotional nuances and leaves you wanting to pause and let revelations percolate.

But perhaps that is the point of this fast pace: as strangers listening in, we hear everything yet always feel a few steps behind and detached from the repercussions.