Young swordsman d'Artagnan arrives in Paris seeking the man responsible for killing his father – a quest that brings him into conflict with one of the king's guards. But as he quickly discovers, when you take on one Musketeer, you take on them all. It's soon back to business when the swashbuckling heroes are ordered to find a missing soldier who was carrying important letters on behalf of King Louis, while the dastardly Cardinal Richelieu plots to increase his political power.
Notorious criminal Vadim seeks to make life unbearable for the authorities that have imprisoned him. When he engineers a full-scale riot, it falls to the Musketeers to protect those whom he seeks to destroy.
Porthos wakes up after his drunken birthday celebrations with a dead body next to him. The Musketeers must prove his innocence as he gets sentenced to death.
Milady seeks her revenge against the Musketeers. Will the Musketeers outwit her or will she destroy them by manipulating their weakest link, D'Artagnan?