"So this is what it looks like with an N of eighteen," Alastair mused over a bottle of Corona. Saskia had spent enough time with him to recognize this as statistician-speak. Launching a single shell—an N of 1—would have taught T.R. a lot. Launching two would have taught him a little more. An N of eighteen was big enough to do some statistical analysis and get a picture of the range of outcomes.