Introduction -- Phenomenon. Cosmic horror ; Dr Jekyll and Mrs Slime ; The stench of death -- Physics. Water in chains ; Stuck on slip-ups ; Shifting boundaries -- Organism. The human fortress ; An arms race with microbes ; The illusory individual -- Life. On the hunt for ur-slime ; The origins of life on Earth ; The substance of life ; The art of vibration -- Evolution. City of microbes ; One long melody ; The Gelata Era -- Nature. The magic of the medium ; Life under water ; Between two worlds ; On dry land ; Roots, shoots and leaves -- Environment. Gaia and the gel ; The skin of the sea ; The contours of the world ; The Earth's living crust ; Medea and the new era -- Afterword: Space slimes.