Mammoth Books presents Monsters in Our Midst - Three Stories by Michael Marshall Smith, Gary Kilworth and John Langan

Substitutions - Michael Marshall SmithMichael Marshall Smith recalls: "This story came about in the simplest way, the way I always enjoy most - something happening in real life that makes you think 'What if?' "Our household gets a lot of its food via an online delivery service, and one day when I was unpacking what had just been dropped at our house I gradually realised there was something...not quite right about the contents of the bags."There's two things that are strange about that experience.
The first is that - given that every household is likely to buy at least some things in common - you don't realise straight away that you've been given the wrong shopping. You don't immediately think 'This is wrong', more like .