Philip K. Dick's Do Androids Dream of Electric Sheep? is a far grimmer story for the entirety of its narrative, even if Blade Runner isn't exactly peachy either. Beats elided from the film include Deckard cheating on his wife with the replicant Rachel, and after he ends up terminating all of the replicants he's tasked with, Rachel ends up pushing his pet goat off a roof to its death in revenge. This is seen as particularly devastating because animals have become a status symbol in this dystopia; they are highly valued because nuclear fallout has killed most of them. The book ends with the suggestion that Deckard may well become mentally disabled in the future due to radiation exposure. The film, on the other hand, asks a far more tantalising question - what if Deckard is a replicant himself? It's one of the all-time brilliant cliffhangers that causes the audience to re-evaluate everything they've seen, providing bleak food-for-thought rather than just being hopeless for its own sake.