"Doctor," Mitchell said quickly, "I know it's a tremendous favor to ask of a man of your position. But you can understand our problem. Unless we can produce quick, conclusive and dramatic proof of our studies we can get no more financial backing. We _should_ run a large-scale field test. But we haven't the time or money for that. We can cure the headaches of one person and that's the limit of our resources." "I'm tempted," Macklin said hesitantly, "but the answer is go. I mean '_no_'. I'd like to help you out, but I'm afraid I owe too much to others to take the rest--the risk, I mean." Macklin ran the back of his knuckles across his forehead. "I really would like to take you up on it. When I start making slips like that it means another attack of migraine. The drilling, grinding pain through my temples and around my eyeballs. The flashes of light, the rioting pools of color playing on the back of my lids. Ugh." Ferris smiled. "Gynergen makes you sick, does it, doctor? Produces nausea, eh? The pain of that turns you almost wrong side out, doesn't it? You aren't much better off with it than without, are you? I've heard some say they preferred the migraine." Macklin carefully arranged his pipe along with the tools he used to tend it in a worn leather case. "Tell me," he said, "what is the worst that could happen to me?" "Low blood pressure," Ferris said. "That's not so bad," Macklin said. "How low can it get?" "When your heart stops, your blood pressure goes to its lowest point," Mitchell said. A dew of perspiration had bloomed on Macklin's forehead. "Is there much risk of that?" "Practically none," Mitchell said. "We have to give you the worst possibilities. _All_ our test animals survived and seem perfectly happy and contented. As I said, the virus is self-stabilizing. Ferris and I are confident that there is no danger.... But we may be wrong." Macklin held his head in both hands. "Why did you two select _me_?" "You're an important man, doctor," Ferris said. "Nobody would care if Mitchell or I cured ourselves of headaches--they might not even believe us if we said we did. But the proper authorities will believe a man of your reputation. Besides, neither of us has a record of chronic migraine. You do." "Yes, I do," Macklin said. "Very well. Go ahead. Give me your injection." Mitchell cleared his throat. "Are you positive, doctor?" he asked uncertainly. "Perhaps you would like a few days to think it over." "No! I'm ready. Go ahead, right now." "There's a simple release," Ferris said smoothly. Macklin groped in his pocket for a pen. II "Ferris!" Mitchell yelled, slamming the laboratory door behind him. "Right here," the small man said briskly. He was sitting at a work table, penciling notes. "I've been expecting you." "Doctor--Harold--you shouldn't have given this story to the newspapers," Mitchell said. He tapped the back of his hand against the folded paper.