They call Verity 'the app-whisperer', and she's just been hired by a shadowy start-up to evaluate a pair-of-glasses-cum-digital-assistant called Eunice. Only Eunice has other ideas.
Pretty soon, Verity knows that Eunice is smarter than anyone she's ever met, conceals some serious capabilities and is profoundly paranoid - which is just as well since suddenly some bad people are after Verity.
Meanwhile, in a post-apocalyptic London a century from now, PR fixer Wilf Netherton is tasked by all-seeing policewoman Ainsley Lowbeer with interfering in the alternative past in which Verity and Eunice exist. It appears something nasty is about to happen there - and fixing it will require not only Eunice's unique human-AI skillset but also a little help from the future.
A future which Verity soon fears may never be . . .