Judith was moved to the Apocrypha for a few reasons. There's too many historical anchronisms to take the text at face value (Nebuchadnezzar being king of the wrong kingdom, for instance). It's seen more as an allegorical tale for the time it was written in, between the 2nd and 1st century BC.
It begins by describing the wars between Nebuchadnezzar and king Arphaxad, where Arphaxad is killed. Victorious, Nebuchadnezzar gloats like a monologuing villain in Chapter 2, telling his chief captain Holofernes to spread the word that he will smite all his enemies.
7 And thou shalt declare unto that they prepare for me earth and water: for I will go forth in my wrath against them and will cover the whole face of the earth with the feet of mine army, and I will give them for a spoil unto them:So Holofernes takes his army of 120,000 and destroys city after city for his king. In Chapter 3, after so many cities have been destroyed, ambassadors of peace come to Holofernes and beg for peace, making offers that Holofernes ignores, as his orders are to wipe out all the other gods in Nebuchadnezzar's kingdom. In Chapter 4, the children of Israel prepare for war, as they know Holofernes will want to tear down the temple in Jerusalem. They also cry unto God and put on sackcloth and make burnt offerings, praying for deliverance.
8 So that their slain shall fill their valleys and brooks and the river shall be filled with their dead, till it overflow:
9 And I will lead them captives to the utmost parts of all the earth.
10 Thou therefore shalt go forth. and take beforehand for me all their coasts: and if they will yield themselves unto thee, thou shalt reserve them for me till the day of their punishment.
11 But concerning them that rebel, let not thine eye spare them; but put them to the slaughter, and spoil them wheresoever thou goest.
Chapter 5, Holofernes is actually offended the Israelites plan to defend themselves, and one of his captains, Achior, gives him a brief history of the people, including how God parted the Red Sea to help them flee Egypt. He ultimately advises not attacking them, for God might help them in battle.
17 And whilst they sinned not before their God, they prospered, because the God that hateth iniquity was with them.Chapter 6 sees Holofernes angry at Achior for daring say such things, so he has his men bind and throw him at the bottom of a hill between their camps. The Israelites find him, untie him, and bring him back to their city Bethulia (Bethlahem?) and appear before their leaders. Achior tells them everything that had been said.
18 But when they departed from the way which he appointed them, they were destroyed in many battles very sore, and were led captives into a land that was not their's, and the temple of their God was cast to the ground, and their cities were taken by the enemies.
19 But now are they returned to their God, and are come up from the places where they were scattered, and have possessed Jerusalem, where their sanctuary is, and are seated in the hill country; for it was desolate.
20 Now therefore, my lord and governor, if there be any error against this people, and they sin against their God, let us consider that this shall be their ruin, and let us go up, and we shall overcome them.
21 But if there be no iniquity in their nation, let my lord now pass by, lest their Lord defend them, and their God be for them, and we become a reproach before all the world.
18 Then the people fell down and worshipped God, and cried unto God. saying,Chapter 7 - Holofernes has his army surround the city and cut off their water supply. The Israelites fear they're going to die of thirst, but the chief governor Ozias tells his people to trust in the Lord, but if the siege lasts five days and they are not delivered, then they'll surrender.
19 O Lord God of heaven, behold their pride, and pity the low estate of our nation, and look upon the face of those that are sanctified unto thee this day.
20 Then they comforted Achior, and praised him greatly.
Chapter 8 is the first appearance of Judith. It gives her lineage back to Israel (Jacob) but through Salasadal. (It's supposed to be Simeon.) Judith is a widow, but well off thanks to her husband's lands and possessions, and Judith has a reputation for being a virtuous, God-fearing woman. She calls the governors of Bethulia to meet with her, and Ozias and the others come to her house (which indicates her status in the city).
11 And they came unto her, and she said unto them, Hear me now, O ye governors of the inhabitants of Bethulia: for your words that ye have spoken before the people this day are not right, touching this oath which ye made and pronounced between God and you, and have promised to deliver the city to our enemies, unless within these days the Lord turn to help you.
12 And now who are ye that have tempted God this day, and stand instead of God among the children of men?
13 And now try the Lord Almighty, but ye shall never know any thing.
14 For ye cannot find the depth of the heart of man, neither can ye perceive the things that he thinketh: then how can ye search out God, that hath made all these things, and know his mind, or comprehend his purpose? Nay, my brethren, provoke not the Lord our God to anger.
15 For if he will not help us within these five days, he hath power to defend us when he will, even every day, or to destroy us before our enemies.
16 Do not bind the counsels of the Lord our God: for God is not as man, that he may be threatened; neither is he as the son of man, that he should be wavering.
17 Therefore let us wait for salvation of him, and call upon him to help us, and he will hear our voice, if it please him.
24 Now therefore, O brethren, let us shew an example to our brethren, because their hearts depend upon us, and the sanctuary, and the house, and the altar, rest upon us.Judith then lets them know she has a secret plan, and Ozias lets her know they trust her.
25 Moreover let us give thanks to the Lord our God, which trieth us, even as he did our fathers.
26 Remember what things he did to Abraham, and how he tried Isaac, and what happened to Jacob in Mesopotamia of Syria, when he kept the sheep of Laban his mother's brother.
27 For he hath not tried us in the fire, as he did them, for the examination of their hearts, neither hath he taken vengeance on us: but the Lord doth scourge them that come near unto him, to admonish them.
28 Then said Ozias to her, All that thou hast spoken hast thou spoken with a good heart, and there is none that may gainsay thy words.
29 For this is not the first day wherein thy wisdom is manifested; but from the beginning of thy days all the people have known thy understanding, because the disposition of thine heart is good.
In Chapter 9, she prays to the Lord, recounting some of the horrible things Simeon did (remember when he and Levi convinced the men of a city to get circumsized, and while they were recovering, the two brothers killed all the men?), but it all was justified. Now she prays for the Lord to justify what she's about to do, in order to deliver her people. She prays for the wrath of the Lord to smite their enemies.
9 Behold their pride, and send thy wrath upon their heads: give into mine hand, which am a widow, the power that I have conceived.In Chapter 10, she dolls herself up as best she can, and Ozias worships God over how beautiful she's made herself, and that her plan will work. She heads to the Assyrian camp, where soldiers take her, and she says she'd fled Bethulia to warn and advise Holofernes. She's so beautiful the soldiers figure she must be telling the truth.
10 Smite by the deceit of my lips the servant with the prince, and the prince with the servant: break down their stateliness by the hand of a woman.
11 For thy power standeth not in multitude nor thy might in strong men: for thou art a God of the afflicted, an helper of the oppressed, an upholder of the weak, a protector of the forlorn, a saviour of them that are without hope.
12 I pray thee, I pray thee, O God of my father, and God of the inheritance of Israel, Lord of the heavens and earth, Creator of the waters, king of every creature, hear thou my prayer:
13 And make my speech and deceit to be their wound and stripe, who have purposed cruel things against thy covenant, and thy hallowed house, and against the top of Sion, and against the house of the possession of thy children.
14 And make every nation and tribe to acknowledge that thou art the God of all power and might, and that there is none other that protecteth the people of Israel but thou.
19 And they wondered at her beauty, and admired the children of Israel because of her, and every one said to his neighbour, Who would despise this people, that have among them such women? surely it is not good that one man of them be left who being let go might deceive the whole earth.Chapter 11, Holofernes takes her in, and she lets him know that Achior had warned them, but she assures him tha God won't helpe Israel, as they have been sinful, and she praises the righteousness of Holofernes' cause. Holofernes believes her and say she will be renowned for the help she's giving them.
Chapter 12 - She stays with their camp for three days, but she will not eat and drink with them. She says she doesn't want to give in to their ways until Bethulia's been taken, but by day four, this is bothering Holofernes, and he insists she join them and eat their meat and drink their wine. She agrees and joins them, and Holofernes is so happy he gets very drunk from celebration.
Chapter 13 - Holofernes is passed out in his bed from being drunk, and Judith prays for strength. She takes Holofernes' sword and cuts off his head with two strikes. She gives the head to her handmaiden, and they sneak out of the camp with his head, and they return to Bethulia.
14 Then she said to them with a loud voice, Praise, praise God, praise God, I say, for he hath not taken away his mercy from the house of Israel, but hath destroyed our enemies by mine hands this night.The Israelites rejoice some more and plan their next move. Chapter 14, Judith tells them to hang the head from the highest wall. They show it to Achior, who confirms it is indeed Holofernes' head. When Achior hears her repeat what she'd done, he gets circumsized that day and counts himself as an Israelite.
15 So she took the head out of the bag, and shewed it, and said unto them, behold the head of Holofernes, the chief captain of the army of Assur, and behold the canopy, wherein he did lie in his drunkenness; and the Lord hath smitten him by the hand of a woman.
16 As the Lord liveth, who hath kept me in my way that I went, my countenance hath deceived him to his destruction, and yet hath he not committed sin with me, to defile and shame me.
17 Then all the people were wonderfully astonished, and bowed themselves and worshipped God, and said with one accord, Blessed be thou, O our God, which hast this day brought to nought the enemies of thy people.
Meanwhile the Assyrians are horrified the next morning when they find Judith gone, and Holofernes headless.
Chapter 15, the Israelites wipe out the Assyrians in battle, and Judith is honored in a victory celebration, which includes singing and dancing.
Chapter 16, Judith sings her song:
13 I will sing unto the Lord a new song: O Lord, thou art great and glorious, wonderful in strength, and invincible.The celebration goes on for three months, and Judith lives to the ripe old age of 105 before she dies.
14 Let all creatures serve thee: for thou spakest, and they were made, thou didst send forth thy spirit, and it created them, and there is none that can resist thy voice.
15 For the mountains shall be moved from their foundations with the waters, the rocks shall melt as wax at thy presence: yet thou art merciful to them that fear thee.
16 For all sacrifice is too little for a sweet savour unto thee, and all the fat is not sufficient for thy burnt offering: but he that feareth the Lord is great at all times.
17 Woe to the nations that rise up against my kindred! the Lord Almighty will take vengeance of them in the day of judgment, in putting fire and worms in their flesh; and they shall feel them, and weep for ever.
I didn't get anything spiritual out of it, but I did find the parallel interesting between Judith cutting off Holofernes' head, and Nephi cutting off Laban's head in the Book of Mormon.