Samuel Takes a Break review – a stomach-churning tourist trip around an old slave castle

He could snap at any second … Fode Simbo as Samuel in Samuel Takes a Break. Photograph: Marc Brenner

‘Welcome to my first tour of the day,” says Samuel to the audience. We’re in the courtyard of a former slave castle in Ghana’s Cape Coast which housed more than three million Ghanaians between the late 17th and 19th centuries, before they were shipped across the Atlantic. But today it is a tourist destination and Samuel is our guide. He’s here to show us around, get to know us, and teach the group the history of the castle as part of the country’s “Year of Return” initiative. “I love this job,” he swears.

But this is no relaxing holiday. Samuel Takes a Break … In Male Dungeon No 5 After a Long But Generally Successful Day of Tours (to give Rhianna Ilube’s play its full title) is a forensic cross-examination of the dark tourism industry. Ilube digs deep into colonialism’s impact on British identity and asks, poignantly, how we are supposed to preserve the horrors of the past. “We don’t like the word slave here,” says Samuel to his guests. With such a charged argument at its core, the narrative sometimes slips into polemic. And yet Ilube’s writing still makes you shake, laugh and not for one second forget the castle’s past.

A pair of British tourists – Letty and Trev – arrive on a pilgrimage of self-discovery. Letty, who is mixed-raced, is here to reconnect with her roots: “This is where it all started,” she says. But with the tourists – and even the ticket booth worker, Orange – failing to properly understand the site’s oppressive significance, Samuel starts to fall apart.

History is folded into the present in Anthony Simpson-Pike’s production. The horrific shadows of yesterday are projected on to the back walls of the theatre, their memory lying dormant but immutable in the castle’s structure. There are short interludes in which we visit Samuel’s psyche – there are flashes of eye-wateringly bright light and underscores of low, mangled resonance. All of it makes your stomach churn.

And with Fode Simbo as Samuel at the helm, it is lyrically enacted. He shudders and then is immobilised by the cave’s ghosts. He seems physically repulsed by the guests’ requests for selfies. But he knows, still, his job is to give them the most authentic tour possible. He could snap at any second, and Ilube’s strength as a writer is willing us to make him shout out.

• At Yard theatre, London, until 23 March