Again, we can see why this novel is called one of the best swashbuckling, "cloak and dagger" adventure novels. In Chapter 20, the four adventurers embark on a mission and encounter all sorts of unexpected obstacles. Without a doubt, the cardinal seems to be able to know exactly what everyone in the kingdom is doing. Remember that Treville warned d'Artagnan about this very possibility.
On the trip to London, the musketeers and d'Artagnan encounter difficulty at the first inn and leave Porthos. Then during an ambush along the road, they believe that Mousqueton is killed; they know that Aramis is wounded, so they leave him at an inn, tended by his servant, Bazin. Later, Athos is falsely accused by an innkeeper of trying to pass counterfeit money and is attacked by four men. Finally, when d'Artagnan and his servant reach the port of Calais, they discover that the cardinal has had the port closed and is sending one of his men, Count de Wardes, with a special permit to London. Clearly when this novel was written, episodes such as these were truly adventures on the highroads.
The story then continues with d'Artagnan's encounter with the duke of Buckingham and the revelation of the duke's power. Since this novel is also a romantic novel, Dumas's emphasis is often on the power of love. D'Artagnan is in awe of the duke's willingness to use all of his power in the service of his beloved Anne of Austria, queen of France. However, we should remember that this adventure which d'Artagnan undertakes (during which he proves himself to be resolute, brave, and ingenious) is undertaken because of his own devoted love for Constance Bonacieux. Thus we have two plots of love and adventure: one centering on court intrigues; the other, on the romantic intrigues of a daring adventurer and his beloved.
