The deadlocked jury in the Lindsay Clancy trial has gone home again without a verdict. The dramatic sixth day of deliberations Thursday saw the jury’s foreperson send the judge a note saying a single juror won’t follow the court’s instructions about reasonable doubt. Details of the jury room conflict weren’t revealed by the judge. But they raised the possibility that a single holdout was standing in the way of a verdict on whether the Massachusetts mother is criminally responsible for killing her three children. Clancy does not deny she did it, but argues that postpartum psychosis led to her actions. The jury will return Friday.