Nazir 63: The Matter Has Legs

A Nazir who has reached the point of shaving, and then encounters impurity - depending on the kind of impurity, he might need to cancel the nezirut days. But if it was utterly unknown (tehom), he doesn't redo the nezirut. Plus, the case of a person who goes to dunk in the water of a cave, and while there, encounters a dead body - he may or may not encounter impurity. Potentially depending on what the status had been prior to the encounter. Also, the case of the person who can't pass a dead body in the street, because it's literally blocking his way. Which opens up all kinds of issues with regard to whether the person walking can remain pure or not.