Witnesses shall be first examined-in-chief then (if the advere party so desires) cross-examined, then (if the party calling him so desires) re-examined.The examination and cross-examination must relate to relevant facts, but the cross-examination need not be confined to the facts to which the witness testified on his examination-in-chief.Direction of re-examination. - The re-examination shall be directed to the explanation of the matters referred to in cross-examination; and, if new matter is, by permission of the Court, introduced in re-examination, the adverse party may further cross-examine upon that matter.