room in the federal court house on constitution avenue in downtown washington. they are struck first by how commonplace the setting feels. more classroom than courtroom, two witnesses said. one of special counsel robert mueller s prosecutors stands at the lectern. the jurors diverse by age and ethnicity are attentive and take notes. the questioning is polite yet aggressive, surprising witnesses with his precision and often accompanied by evidence including text messages and e-mails, displayed on a large old-fashioned overhead projector. and this description of the man at the helm. mueller the 73-year-old former fbi director with the hang dog massage and rigid bearing looms over the investigation but is an intermittent presence in the windowless room in the courthouse. robert mueller s investigation has been described to me not as an iceberg with most hidden under the surface but as an underground village where everything is concealed and we have very little idea of what is happening as