on Earth, but the attack led to mass purges and complete shutdown of Nexus-8 production (though many existing units were able to go into hiding in the chaos). In 2036, genetic engineer Niander Wallace designed a new line of Nexus-9 replicants. They also have an open lifespan, but were designed to be unable to resist orders given by a human. The demonstrated effectiveness of Nexus-9 programming, combined with the solving of a global food crisis, allowed for a successful push for the ban on replicant production to be lifted. By 2049, Nexus-9 replicants are extensively used across Earth and the off-world colonies. Special police units are tasked with tracking down any that might go rogue, as well as any remaining Nexus-8s still in hiding (Nexus-7 was never mass-produced, and all the Nexus-6 models died of old age decades before). These police units are once again called Blade Runners, but are now composed of self-aware replicants with implanted memories, though they are fully aware that they are replicants and that their memories are artificial. Ambiguity over Deckard's Humanity A primary element of the Blade Runner film is the ambiguity over whether the protagonist, Deckard, is a human or a replicant. This ties into one of the central themes of the film: the nature of humanity. Ultimately, the important point is not whether Deckard is a replicant but that the ambiguity blurs the line between humans and replicants. Creator opinions Harrison Ford, who played Deckard in the film, has said that he did not think Deckard is a replicant, and that he and director Ridley Scott had discussions that ended in the agreement that the character was human. According to several interviews with director Ridley Scott, Deckard is a replicant. When asked about the possibility of a Blade Runner sequel in October 2012, Scott said, "It's not a rumor—it's happening. With Harrison Ford? I don't know yet. Is he too old? Well, he was a Nexus-6, so we don't know how long he can live. And that's all I'm going to say at this stage." Author Will Brooker has written that unicorn dream may not be unique to Deckard and that it may be a personal touch added to some or all of the Nexus-6 replicants' brains. From this, one might also infer that Gaff is a replicant and shares the same embedded memory. Paul Sammon, author of Future Noir: The Making