Ebola is back. In 2014, it killed over 11,000 people in West Africa. Now the disease has struck once again in the Democratic Republic of Congo. This time doctors are better equipped, with a vaccine and immunisation campaign but the outbreak highlights the ever-present dangers posed by infectious diseases. One hundred years ago the Spanish flu killed over 50 million people in just one year. And doctors now say the next pandemic will be upon us in a matter of decades. We don't know where it will start but in a hyper-connected world we know it will spread easily. Ritula Shah asks a panel of expert guests about the scenarios that keep them up at night and whether global health infrastructure is ready for the coming pandemic.