We frequently take the plunge, artistically speaking, at the North Wall, a venue fashioned from a former swimming pool and known for adventurous programming.

This was certainly the case on Friday, when Ridiculusmus brought us their startling four-hander The Eradication of Schizophrenia in Western Lapland.

A hit at last year’s Edinburgh Festival, the play, penned by cast members Jon Haynes and David Woods, has since been been garnering rave reviews out on tour.

Slightly puzzled ones, too, for there is more to bewilder than the title (of which more presently) here.

In an interesting conceit from the audience’s point of view, spectators are divided into two camps, at opposite ends of the auditorium with the show taking place in a central stage on two sides of a dividing wall. At half time, we all swap places to the other side.

For the first half, I watched what was clearly a confrontation between a psychiatric patient (Jon Haynes) and his shrink (David Woods). Among the delusions entertained by the former is that he had pseudonymously penned the entire oeuvres of Vladimir Nabokov and Edna O’Brien. At one point mention is made of The Eradication of Schizophrenia in Western Lapland.

“What’s that?” inquires the doctor. “It’s the play we are in.”

Every so often there are irruptions from the other side by a character (Richard Talbot) whose shaved head and features make him a dead ringer for the doctor. Later we learn of the domestic drama in which he and his mother (Patrizia Paolini) are involved as the performance is repeated once we have shifted seats. Lines dimly overheard in part one take on a different meaning in the new context.

In the final minutes the curtain dividing consulting room and sitting room comes down and all becomes clear(ish).