Bacteria have established various strategies to infect organisms and use them as sources of nutrients. Many microbes use toxins that break down membranes by simply piercing through the outer shell of the cells. Human-pathogenic bacteria such as the plague bacterium Yersinia pestis or other bacteria from the salmonella family developed a much more subtle mechanism: they inject their poison by applying a special toxin complex. A team of researchers led by Stefan Raunser from the Max Planck Institute of Molecular Physiology in Dortmund has now been able to fully unveil the sophisticated mechanism using the bacterium Photorhabdus luminescens as an example.