The work described herein does not take malaria’s complexity for granted. The stage is Ethiopia, specifically the southwestern highlands about 1750 meters above sea level, where malaria outbreaks are mostly what malariologists call “unstable”: a condition where transmission is spotty and outbreaks don’t occur each year. The altitude and the associated cool temperatures slow development of the parasite within the mosquito. Few mosquitoes survive sufficiently long to acquire, incubate, and then pass along the infectious agent to new human hosts. This limits people’s exposure and makes the “shivering fever” periodic yet especially deadly as inhabitants have little or no acquired immunity to the disease. As in many other places in sub-Saharan Africa, the local ecological landscape is in transition, affected by climate change, migration, and agricultural practices. These all conspire to precipitate predictable as well as unexpected changes in the composition and abundance of mosquito populations, with deadly consequences.