In the final third of Blade Runner 2049(Villeneuve, 2017) Harrison Ford's aged and haggard Deckard encounters an eternally youthful replica of Sean Young's Rachael, the replicant with whom he fell in love in Ridley Scott's original 1982 movie. Rachael is long dead, but Jared Leto's villain CEO, Wallace, offers Deckard this copy, ‘an angel remade anew’, as a bribe for information. The film seems to hold its breath with Deckard as she comes into view – first as a silhouette, recognisable by her sleek pompadour, the exaggerated Noir shoulders of her suit, and the assured click-clack of her heels on the floor – giving us a moment of anticipation for the sight of her face. Those of us familiar with the iconic character are invited to wonder: how will this Rachael be achieved, and how persuasive will she be? Emerging from the sulphurous gloom, the figure glides slowly towards us, her face immobile and doll-like as its details – the mascara-ringed doe eyes and the glossy painted lips in relief against unmarked porcelain – loom into increased clarity. Finally, in close-up, presented for scrutiny, Rachael's copy asks, ‘Did you miss me? Don't you love me?’ Deckard's response urges us to believe that in visual terms, the illusion is perfect. His face sags, mouth agape, trying to process the figure before him. Finally, grasping through his memory, he rejects her with a phony excuse: ‘Her eyes were green,’ he growls, before wrenching himself away. While for Deckard she is a copy of what he has lost and longed for, for us she is a digital replica of a younger version of a human actress and, accordingly, her face is offered to us as a spectacular visual effect – a complex assemblage of labour, skill, time, money, software, performances, and anatomical observation and knowledge. As the film's publicity tells us, visual effects (VFX) supervisor John Nelson worked on her for a year and cited her as the biggest challenge of his career, saying, ‘Digital humans are sort of like the holy grail — they’re really hard.’

Since the 1980s, ‘holy grail’ has been a common term for a persistent goal in digital visual effects: that of crafting a fully expressive photorealistic digital human for cinema, indistinguishable from a living actor.