There is no lock on the door, no phalanx of guards, no visible impediment to the drugs leaving the glass chamber that the laboratory technicians call a "stability room". The pills come in little white boxes with labels such as lamivudine, zidovudine and efavirenz, technical names disguising the fact that these tablets are the stuff of life. Take them together and if you have HIV you can stave off death for years. Millions in Africa have the virus but not the pills. A stone's throw from the laboratory Aids is wiping out communities, yet these pills cannot leave the stability room.