In 1648, Sir Edmund Blackadder, descendant of Prince Edmund Plantagent and currently the sole member of the noble dynasty, is one of two people who stayed loyal to King Charles I after Oliver Cromwell's threat, the other being Baldrick, descendant of a pig farmer and a bearded lady. To protect his liege, Sir Edmund has hid the king (the series has already proven to us that the royals are insane) in Blackadder Hall, but Baldrick unwittingly betrays the ruler when Cromwell arrives at the Hall. Blackadder decides he must save the king when he is sentenced to execution, and becomes frustrated when Baldrick cluelessly accepts a job as executioner- until he realizes he may be able to use it to save Charles...
