It's now about time for Una to think about her parents, who are captured by the dragon. She tells Redcrosse that they are now near her home and he needs to be ready for battle.
She points to a tower in the distance, where her parents are, and all of sudden they hear and see the terrible dragon, who, seeing them, gets ready for a fight.
Redcrosse sends Una away to watch from a hill and our narrator interrupts to call upon his muse for help in telling this particularly important and bloody part of the story.
Back to the action, the massive dragon is approaching fast, half-flying, half-running.
He's covered in impenetrable scales, has wings as large as a ship's sails, has a humongous, pointy tail, fearful, gruesome jaws that still are full of the blood and entrails of his former victims, and blazing, fire-filled eyes.
Redcrosse gets a little bit concerned as this beast heads straight for him, and after being knocked over once, manages to hit the dragon but not penetrate him.
His hit is strong enough, however, to make the dragon upset and the dragon flies up into the air with great force and carries Redcrosse and his horse far away.
Once Redcrosse is finally able to get free, he is able to wound the dragon under the neck, a wound that gushes so much blood, the land around them is partially flooded.
The dragon then uses his tail to trap the horse and Redcrosse tries to wound the dragon again, but without success.
The dragon becomes so angry about being continually hit that he releases a huge breath of fire that burns Redcrosse right through his armor.
Poor Redcrosse is so exhausted and injured he wants to die, but, in a moment of great good luck, Redcrosse finds himself near a magical fountain called the "Well Of Life," which can bring people back from the dead and heal the injured.
The dragon throws Redcrosse into this well and leaves him there over night, believing that he, the dragon, has now won.
Una, terrified, prays all night long for help.
In the morning, Una wakes up and looks to see how Redcrosse is doing.
She's amazed and delighted to see him rise from the fountain good-as-new, totally healed and stronger than ever.
The dragon is understandably perplexed and concerned by this development, and Redcrosse, just to prove his newfound strength, deals the dragon a painful blow to his skull—something that has never been done before.
The dragon is furious and stabs Redcrosse with his poisonous tail right in the shoulder.
Although the wound is severe, Redcrosse, focusing on his pledge to Una and angered at the dragon's success, slices off his tail.
The dragon in return grabs Redcrosse's shield, which Redcrosse doesn't want to lose but can't pull away from the dragon.
Finally, he cuts the dragon's joint in two, even though the dragon's paw remains holding on to the shield.
The dragon then lights up the whole sky with fire and black smoke, like a volcano, and Redcrosse has to retreat a bit to avoid the heat.
He then falls backward, which ends up saving him through God's mercy (even though he's super embarrassed about tripping), because he falls into another life-saving stream.
This guy is super-lucky.
This stream actually runs from the tree of life, a tree that God planted in Eden that is mentioned in the book of Genesis.
Since night is falling, and since the dragon can't come near this holy space, the two take another timeout.
Una, seeing Redcrosse fall again, runs to him and applies the healing balm Arthur gave him to his wounded body.
When morning comes, Redcrosse wakes up right-as-rain, which yet again perturbs the frustrated dragon.
The dragon rushes at Redcrosse with his jaw open, hoping for breakfast, only to have Redcrosse stab him right in the mouth and kill him.
The dragon falls to the ground with a huge thump and both Redcrosse and Una can hardly believe it has truly happened.
As soon as Una realizes the dragon truly is dead, she thanks her knight and prays to God.