In the summer of 1783, an unusual dry fog descended upon large parts of the northern hemisphere. The fog brought with it bloodred sunsets, a foul sulfuric odor, and a host of other peculiar weather events. Inspired by the Enlightenment, many naturalists attempted to find reasonable explanations for these occurrences. Between 8 June 1783 and 7 February 1784, a 27-kilometer-long fissure volcano erupted in the Icelandic highlands. It produced the largest volume of lava released by any volcanic eruption on planet Earth in the last millennium. In Iceland, the eruption led to the death of one-fifth of the population. The jetstream carried its volcanic gases further afield to Europe and beyond, where they settled as a fog, the origin of which puzzled naturalists and laypersons. "A Mist Connection" is an environmental history that documents the Laki eruption and its consequences for Iceland and the wider world. The book combines methods of historical disaster research, climate history, global history, history of science, and geology in an interdisciplinary approach. Icelandic flood lava eruptions of this scale have a statistical recurrence period of 200 to 500 years; it is crucial to understand their nature so that we can prepare for the next one. An eruption of this magnitude would surely be disastrous for our modern, globalized, and interconnected world.