Read the excerpt from The Time Traveler's Guide to Elizabethan England . But what if it comes to the worst? What if you have painful black buboes in your groin and armpits, and experience the rapid pulse, the headaches, the terrific thirst, and delirium that are the tokens of the plague? There is little you can do. Physicians will prescribe the traditional medicines of dragon water, mithridatium, and theriac if they hear you are suffering but you will suspect that these are cynical attempts to relieve a dying person of his money. The physicians themselves will not normally come near you. Simon Forman, who does attend plague sufferers, is a rare exception: this is because he has himself survived the disease and believes he cannot catch it again. What is the central idea of this paragraph?