When our grandparents were young, there was no such thing as an antibiotic. Diseases like tuberculosis were invariably fatal. In the twentieth century, the fortuitous discoveries of penicillin from a mold and streptomycin from soil made a revolution in medicine. Today, we have even more powerful antibiotics, but also more powerful bugs evolving to outwit them. The large pharmaceutical companies spend billions of dollars seeking new antibiotics through trial and error searches. Now, at SLAC's X-ray source SSRL and other X-ray labs, we are learning to take the next step in drug discovery. With X-rays, we can see the structure of the proteins by which killer bugs do their damage. We can insert fragments of potential drugs and literally watch these grab the atoms by which the proteins act. And now, at SSRL, we can put this process into an assembly line to screen thousands of possible combinations of drug components. This lecture will describe these tools and the route they will give us to more powerful and effective medicines.