D'Artagnan had not been deceived; these two men had only followed for the purpose of assassinating him, hoping that the young man's death would be placed to the account of the enemy.
As he might be only wounded and might denounce their crime, they came up to him with the purpose of making sure.

Fortunately, deceived by d'Artagnan's trick, they neglected to reload their guns.
When they were within ten paces of him, d'Artagnan, who in falling had taken care not to let go his sword, sprang up close to them.
The assassins comprehended that if they fled toward the camp without having killed their man, they should be accused by him; therefore their first idea was to join the enemy.

One of them took his gun by the barrel, and used it as he would a club.

He aimed a terrible blow at d'Artagnan, who avoided it by springing to one side; but by this movement he left a passage free to the bandit, who darted off toward the bastion.

As the Rochellais who guarded the bastion were ignorant of the intentions of the man they saw coming toward them, they fired upon him, and he fell, struck by a ball which broke his shoulder.
Meantime d'Artagnan had thrown himself upon the other soldier, attacking him with his sword.