Canto XVII. There she joins the Christians’ enemies, declaring she dreams of naught save slaying Rinaldo, and takes an important part in the review which the poet describes minutely.  To compass her ends the artful Armida, whose charms have so lavishly been displayed that they have fired every breast, promises to belong to the warrior who will bring her Rinaldo’s head.  Meanwhile this hero has returned to Palestine, and is met by the wizard, who, after reproving him for his dalliance, gives him wonderful armor, and exhibits on the shield the great deeds of ancestors of the Duke of Ferrara.

Canto XVIII. Newly armed, Rinaldo now returns to the crusaders’ camp, apologizes to Godfrey for breaking the rules of the crusade, relates his adventures, and, after humbly confessing his sins, starts forth to brave the spells of the magic forest.  Not only does he penetrate within its precincts, but, undeterred by all Armida’s enchantments, cuts down a tree, although, in hopes of staying his hand, her voice accuses him of cruelly wounding her!  No sooner has this tree fallen than the spell is broken; so other trees are cut down without difficulty, engines built, and all is prepared for a new assault on Jerusalem.

Godfrey is particularly eager to make this new attempt immediately, because a carrier-pigeon has been caught bearing a message from the Egyptians to the Sultan of Jerusalem, apprising him that within five days they will come to his aid.  During this assault of Jerusalem, a sorcerer on the walls, working against the Christians, is slain by a rock.

Soon after, thanks to the efforts of the Crusaders, the banner with the Cross floats over the walls of Jerusalem!

    Then raised the Christians all their long loud shout
    Of Victory, joyful, resonant, and high;
    Their words the towers and temples lengthen out;
    To the glad sound the mountains make reply: 

* * * * *

    Then the whole host pours in, not o’er the walls
    Alone, but through the gates, which soon unclose,
    Batter’d or burnt; and in wide ruin falls
    Each strong defence that might their march oppose. 
    Rages the sword; and Death, the slaught’rer, goes
    ’Twixt Wo and Horror with gigantic tread,
    From street to street; the blood in torrents flows,
    And settles in lagoons, on all sides fed,
  And swell’d with heaps on heaps of dying and of dead.

Canto XIX. Tancred, scaling a fortress, meets and slays Argantes, receiving at the same time so grievous a wound that he swoons on the battle-field.  Meantime Godfrey has sent a spy to the Egyptian camp to find out whether the army is really coming on to Jerusalem.  This spy, meeting Erminia there, induces her not only to reveal all the Egyptians’ plans (including a plot to slay Godfrey), but to go back with him.  While they journey along together to rejoin the Christian forces, Erminia relates her adventures,