The buzz about how easy it is to use the CRISPR/Cas9 genome-editing machinery has inspired the tool’s widespread application. Researchers rave about the simplicity of using the system to cut and paste DNA into a variety of organisms with the aid of an RNA guide. But little is known about the kinetics and search strategy of the wunderkind genome editor, an information vacuum tackled recently by a team of scientists led by Jennifer A. Doudna and Robert Tjian at the University of California, Berkeley, and Zhe Liu at Janelia Research Campus. The team tagged a catalytically inactive version of Cas9 with a fluorescent label and set it loose in mouse cells (Science 2015, DOI: 10.1126/science.aac6572). Then the group watched as Cas9 searched for DNA complementary to the RNA guide. The machinery generally spent less than one second on DNA sequences that did not correspond to the RNA guide. In addition, the team found that Cas9 could penetrate deep into tightly packed DNA called heterochromatin to find its correct match, albeit a little slower than in more accessible sections of the genome. The work reinforces the wide utility of CRISPR/Cas9 genome-editing machinery.