Hush, My Darling... is a side quest in the 
Kuttenberg region of Kingdom Come: Deliverance 2. What begins as a simple favor for a blacksmith's wife quickly spirals into a mystery involving a missing girl, a forbidden romance, and a soldier in 
Sigismund's Camp.
How to start Hush, My Darling… quest
To begin this quest, travel to the village of Miskowitz. Look for Martha, the blacksmith's wife. She can usually be found inside the blacksmith's house or near the yard by the anvil.
Martha will explain that she needs two sets of horseshoes. Her husband, a blacksmith, refuses to do business with Sigismund's camp, so she asks for your help.
Forging the Horseshoes
You need to provide Martha with two sets of horseshoes. Go to the forge in the yard, where Martha's husband smiths. You have two ways to obtain them:
Crafting: Use the nearby blacksmith station. You will need enough Scrap Metal for two sets and the 
Farmer's Horseshoes sketch, or another horseshoe sketch you already know.
Purchasing: The blacksmith sadly doesn't sell any horseshoes, but you can buy the blacksmithing materials from him.
Passing a hard speech check with him may also net you the materials for free, so you can immediately craft them. You need to craft two horseshoes.
Once you have the horseshoes, return to Martha, who will reward you with 60 Groschen.
She will then ask you to deliver them to Victoria, a local girl who lives in the house directly south of the smithy in Miskowitz.
Victoria is Missing
When you arrive at Victoria's home, the house is empty and you will find blood on the floor in the room on the left, which you should investigate.
Return to Martha in Miskowitz to report your findings.
Shocked, Martha suggests two leads:
Kuba: A local farmer who was interested in Victoria.
Sigismund's Camp: Victoria had been seeing a man from the camp.
Investigating Kuba (Optional)
Kuba lives in Miskowitz, just north of the smithy. He isn't helpful and will become hostile if you pressure him. You can fight him, but even if you beat him, he will reveal that he knows nothing.
Despite Kuba being innocent in this, you can pickpocket Kuba to find Victoria's Scarf, which allows Mutt to track her if you have the Houndmaster skill.
This is very, very useful and you can skip a large portion of this quest with this trick.
Start the tracking north of Sigismund's Camp to save some time walking behind the very slow Mutt. If you do this, skip the next section of this guide and follow from the Save Victoria section.
Sigismund's Camp
If you're not going for the scarf shortcut, head to Sigismund's Camp and speak to other characters there.
Almost all soldiers can be interacted with and will pinpoint a blacksmith, who in turn will identify Victoria's contact as a soldier named Black, a member of the provisioning unit.
Treating Black
You will find Black in the hospital tent (
Field infirmary) toward the south of the camp. He is suffering from a severe stomach ailment. To progress, you must treat him:
Passing a survival check reveals he has food poisoning. Hand over a 
Digestive Potion. You can brew this or buy it from an apothecary.
Once cured, you can ask him about Victoria. He will reveal that she was looking for something more serious than he was and is currently hiding in a clearing in the forest near the camp.
Note: This is a timed quest. If you wait too many days after this point, you will find Victoria dead in the forest from poisoning, and the quest will fail.
Save Victoria
Follow the quest marker to the clearing in the forest. You will find Victoria sitting on a stump, her hands covered in blood.
Victoria's Location - Where Mutt Will Also Lead You:
Read the endings section before talking to her! Several dialogue checks simply end the quest, missing out on an achievement and other endings!
While talking to her, you can discover that Victoria is pregnant and deeply in love with Black. At this point, you have several ways to conclude the quest, depending on your answer.
This is the most important decision in this quest.
If you are hoping for the 
Henry the Matchmaker achievement, do NOT tell her that she should forget about him.
All Hush, My Darling Endings
Here are all possible next steps and endings:
She refuses Black and moves to Devil's Den
Pass the skill check "It'd be best if you forgot about him" - tell her to forget about Black, then recommend a new life in Devil's Den.
She refuses Black and moves back home
Pass the skill check "It'd be best if you forgot about him" - tell her to forget about Black, then recommend returning to Martha in Miskowitz.
Lie to her, that Black will take care of her
Choose the second option "He promised he'd take care of you" - lie to her that Black has agreed to stay with her, which will satisfy Victoria.
Ensure Black stays with her by kidnapping him - How to Get Henry the Matchmaker
Choose the last option "Hang in a while longer. I'll be back." To earn this unique trophy, you must physically kidnap and bring Black to Victoria. This is difficult because Black is still in Sigismund's Camp.
The easiest route is through the western gate near the fast travel point, though you may need to stealth-kill 1 - 2 guards to clear the path.
Scout the route during daylight, then skip to midnight and equip stealth gear. Enter the infirmary and knock Black out.
Watch this video to see how to safely get out of camp. You need two guard kills:
one standing inside the camp, but close to the exit, holding a torch
a guard standing at the edge of the infirmary.
Carry Black all the way to the clearing (about a 5-minute walk). Lay him down next to Victoria like this:
Speak to Victoria. Black will wake up - and flee, leaving Victoria alone anyway. This will unlock the Henry the Matchmaker achievement and end the quest.
If you talk to Black after this (he will start moving back to Sigismund's Camp), he will become aggressive and ask for money. This works like a fine system - pay him 240 Groschen, use a skill check or bear punishment.
You can also freely just kill him, he is not necessary for any other quests.
Rewards
There are no major rewards for this quest beyond 60 Groschen for the horseshoes and the potential achievement. Henry also never gave up the horseshoes - you should still have them.
Victoria will return to Miskowitz, but can't be interacted with. Martha has small additional dialogue, but nothing major and no rewards.