hen accepted, is a juror in name only . . . His relation to the court and to the parties is tainted in its origin; it is a mere pretense and sham." Clark v. United States, 289 U.S. 1, 11 (1933). "[A] juror who lies [his] way onto a jury is not really a juror at all; []he is an interloper akin `to a stranger who sneak