The Jaunt side quest becomes available only if you follow the Blacksmith Radovan’s questline to get to the wedding in Semine in Kingdom Come: Deliverance 2. This side quest requires you to hunt down the blacksmith’s missing cart, his goods, and the two hired hands in charge of the cart.
Note that this quest is time-sensitive, so you must come prepared to set off with Lord Semine and Captain Gnarly immediately once you reach Semine. After completing the quest in Kingdom Come Deliverance 2, you will earn 80 Groschen and a Rusty Sheet.
How to Start the Quest?

To unlock this side quest, head over to Blacksmith Radovan in Tachov, complete the initial test, and then the Blacksmith’s Son Quest. Once you have completed the quest, talk to Radovan and ask him for another job. This is when the blacksmith will tell you about the missing cart, and the quest will start.
Head to Semine

As soon as the quest begins, fast travel to Semine, which is southwest of Troskowitz.
Defeat Jurko in a Fight

Once you reach Semine, enter the fortress, and you will encounter a drunkard named Jurko. You need to defeat him in a fist fight. The fight will be pretty simple; you will get a green shield logo to counter his attack and red markers to plan your combo attack.

The fight soon ends as Captain Gnarly walks in.
Meet Gnarly and Lord Semine in the Courtyard
Follow Gnarly to the Courtyard, where you will meet Lord Semine. Before you talk to him, make sure you have a horse. If you don’t, you need to visit the stables and get Pebbles.

When your horse is ready, simply talk to the Lord and choose the “Let’s go” and “We can go” dialogues.
Follow Lord Semine and Gnarly

Follow Lord Semine and Captain Gnarly outside the town. As soon as you reach a pen, Lord Semine will challenge you to a friend duel, which you can accept.
Duel with Lord Semine

Before the duel, Lord Semine will give you his club to fight with. Simply block his attacks and land combos after recharging your stamina.

Once the duel ends, you need to get your performance judged by Captain Gnarly and then carry on to Troskowitz.
Speak with Bailiff Thrush
Follow Gnarly and Lord Semine to Trokowitz. Once you reach the town, you will have to engage in a small conversation with them again.

After talking to them, head inside the building on the north side, open the door on the west side, and enter Scribe Gaibl’s room. Make sure you visit during the daytime; otherwise, you will not find the Bailiff.

Simply exhaust all dialogues to complete the objective.
Head Back to Lord Semine

Head back to Lord Semine and report to him. After that, start following them again.
Investigate the Area of the Crossroads by the Cemetery
Keep going northeast on the road, and you will find a sack of coal lying on the ground. Investigate it and report to Lord Semine.

Investigate the Area of the Crossroads by Apollonia
Once you stop, turn around and head to the west end of the road. You will find another coal sack on the ground.

Keep going northwest from there, and you will find an abandoned cart near the rock wall.

Turn back to report to Lord Semine about the cart and follow them on foot.
Get Closer to the Camp
Once everyone is done inspecting the cart, follow Lord Semine and Gnarly around the camp area looking for bandits. Head up the mountain, stop to talk to them, and they will send you off to scouting.

Go Scouting
After talking, move along the cliff and turn west to find a small path between the rocks. You need to stealthily creep up the path because there will be three bandits.

Report back to Lord Semine and suggest an attack strategy.
Attack the Patrol
As soon as you enter the area, charge at the bandits and take them out.

Once the bandits are out, talk to Captain Gnarly and say “Let’s go” to meet the hired hand.
Attack the Camp

You will get attacked by four bandits. Fight them and agree to catch the prisoner who ran away.
Catch the Hired Hand
Head south from the campsite, jump over the fallen cart, and follow the rocks on the left. Go east on the path between the rocks and immediately take the northwest path. Go up the rocks, and you will find the Hired Hand Ventza.

Talk to the hired hand. You can intimidate him by saying, “You’re no match for me!” and end the conversation. Or you could get more information from him by choosing “Can’t you think of any other solution?” This is when Ventza will try to bribe you and give you Hired Hand Ventza’s Map that leads to the stolen goods.

Note that the former choice will not give you the map.
Go Back to Lord Semine

After returning to Lord Semine, he will hand over 80 Groschen. You can shorten the path by asking for a ride back.
Return to Blacksmith

Head back to Blacksmith Radovan in Tachov and tell him what happened. Note that if you choose “The cart has been found,” he will reward you with a Rusted Plate.
The Jaunt Quest Bug
Many players have experienced getting softlocked on the quest because they didn’t have a horse and went to get one, or they didn’t head out immediately and started doing other tasks. By the time the players return, Gnarly says that Lord Semine ran out of patience and left alone, looking for the cart. If you are experiencing this, please note that the quest is time-sensitive, so you must have a horse and should leave with Lord Semine immediately, or else you will not be able to complete the quest.