It came out over coffee, the way many things do.

In the Bureau of Enigmas, there was an entire department devoted to Mapping, and yet the seven of them rarely consulted.  Each would pick a phenomenon – or, more often, be assigned one – and would map out its trends.

This was not, despite the name, soley geographic mapping, but tracking over time and over demographic notes.

The Bureau covered such a large span of enigmas – cryptids and their wake at one end, the Tiny Ones at the other end – that there was always some trend that needed documenting, some break in reality that needed following and studying so that, if the study itself did not heal it (and in 45.6% of the time, it did), those that were tasked with dealing with such things could do their job equipped with the most information possible. Forewarned is forearmed, the saying went, and in the Bureau of Enigmas, forearmed often meant the difference between life and death.

Still, despite the work, there were always coffee breaks.  And when three Mappers happened to be sipping dark, fresh coffee with the slight taste of the Other-Sphere, they did as all people did, whatever the papers or oaths or soul-binding contacts suggested, and they chatted.

Today they were chatting about three things with no pattern, a plague, a spate of madness, and a serial killer.  None of them appeared to be settling into anything regular.  None of them were predictable, and predictable was important.

Until one mentioned Chicago and the other two stared.

Twenty minutes later, coffee forgotten, they had put their three maps together.  There, in Chicago, there was their nexus.  And from there-

“There’s a method,” one of them breathed.

“It’s madness,” another one muttered.  But most of what they did was madness.

“But it’s a shape,” the third agreed.  “There’s a pattern to the madness.”

They rang an intern to tell Field.  They had their Enigma.

Written To Oct. 25th’s Thimbleful Thursday Prompt, although not really in the wordcount.