The Enemy (Charlie Higson)

The Enemy opens Charlie Higson's seven-book YA horror series, set in London after a mysterious sickness turns every adult into a voracious, flesh-hungry threat and leaves children to fend for themselves in a city gone feral. Each subsequent book (The Dead, The Fear, The Sacrifice, The Fallen, The Hunted, The End) follows different groups of survivors as the outbreak's scope and cause slowly come into focus. Higson also wrote a short companion book, Geeks vs. Zombies, alongside the main series.