Simon McBurney’s legendary theatre company Complicité basically has two modes: clever but fairly narratively conventional takes on difficult-to-stage classics, and brain melting experimental odysseys that’ll rewire your cerebellum.

Their 1999 play ‘Mnemonic’ - reimagined and redevised for 2024 - is very much in the latter camp, although to a certain extent the problem with brain melting experimental odysseys is that they can be hard to describe in a way that accurately conveys their appeal.

Does a play that explores the parallels between the act of memory, the act of migration, the act of ancestry and the act of storytelling sound intrinsically thrilling to you? It doesn’t to me. But it truly is. 

‘Mnemonic’ begins slow, with actor Khalid Abdalla delivering a rambling, slightly Richard Curtis-y speech about the nature of memory, his personal background as a Brit born in Scotland with Egyptian ancestry, and the fact that Compicité is reviving its 25-year-old hit ‘Mnemonic’, with Khalid assuming the role director McBurney originally played.

Eventually it unfurls into two separate strands: the mystery of what happened to Alice (Eileen Walsh), the wife of Omar (Khalid), who abruptly disappeared nine months ago after her mother’s funeral; and a fictionalised version of the true-life mystery of a body discovered on the border of the Austrian and Italian Alps in 1991 due to a freak glacier melt, which was discovered to everyone’s great surprise to have been 5,200 years old.

It’s essentially two mystery stories, staged side by side and then, audaciously, intertwined. One follows Alice on an odyssey through Europe as she haphazardly tries to track down the father she never knew, desperate to find a narrative to her existence now her mum has gone. The other concerns the ‘iceman’ - his discovery, recovery and the scrabble for the international scientific community to impose a narrative on his life. In the middle is Omar, who watches shows about the iceman late into the night while trying to understand what became of Alice, and starts to see strange links between the two.

And this is the key to ‘Mnemonic’ - it is a play about how everything is interconnected, how the winds of migration and the freak Saharan winds that thawed the glacier are in their own way the same idea from a human perspective, how humanity is ultimately defined by its need to see the world through stories and how our reality is fundamentally a patchwork of unknowable things that fire up our neurons. Which possibly sounds dry, but at its graceful peak ‘Mnemonic’ is like coming tantalising close to the meaning of existence, like pulling back some veil that our minds aren’t really yet meant to comprehend.

Again, it could be dry but it isn’t. The company-devised text has not been made aggressively  contemporary but at the same time it has been reimagined almost root and branch for a different cast, and a world of Brexit, smartphones and the Russian invasion of Ukraine (maybe Omar’s obsession with the iceman feels a little more esoteric in 2024 than in 1999, but there have been research developments since then). The Alice strand glows with humanity, the sudden, strange connections she meets with people as she travels through the European night. The iceman thread is a little more thesis-like, but it’s beautifully handled, especially the late comic relief of the scene where a panel of experts each confidently say who they thought he was, each with a different, essentially unprovable opinion. 

And it absolutely wouldn’t work without an extraordinary creative team: it’s hard to pick out an MVP, but the dreamy movement – which deftly interweaves the story’s strands and builds to a jaw dropping final scene – Christopher Shutt’s deft, gracious, sound design and Michael Levine’s gauzy sets picked out by Paul Anderson’s silhouetting lightning design is the mark of creatives at the absolute top of their field.

It starts slow, with the jocular lecture at the start maybe even a smidge irritating, but it builds into something luminous and huge and almost beyond comprehension. Its last few minutes feel like staring overwhelmed at the secrets of creation.