Open Sesame, The Safecracker, Breaking and Entering - The Witcher 3 DLC Hearts of Stone Guide
Open Sesame, The Safecracker, Breaking, and Entering are three short quests in The Witcher 3 DLC Hearts of Stone. Walkthrough of each quest with Tips and Tricks are shared below in The Witcher 3 DLC Hearts of Stone Guide.
You require Level 34 to complete this quest. Simply Head for the marker which will take you to an old associate who will conveniently turn up and grant entry to the auction. Now talk to Vimme's friend upstairs, he is the one with some diagrams for sale such as a game of Gwent and a tip on a painting in the auction. He'll then suggest you to buy the van Kogh pitcher which you've identified.
Now at the auction you are supposed to bid on the items(buying or not is uncertain) and during the intermission you'll be introduced to Borsodi who is going to kick you out, but here a mysterious man will help you out and direct you to the herbalist just outside Oxenfurt. Take Down the soldiers who are banging on his door and interrogate him to know more about the yarrow. He will then take you to his basement and tell you all about his plan and pick your sidekicks.
Casimir: As you arrive he'll threaten to blow himself up. Talk him down (using Axii is the simplest way) and then he'll agree to join you.
Quinto: In the mercenary camp, pay the bounty 200(although this can be haggled over).
Breaking and Entering
Hoff: In Novigrad and knock on the door and use Witcher Sense to examine the bloodstain on the post. Now follow the footprints and when you reach the riverbank Defeat the thugs. Swim to the marked area on the map and You need to dive under to discover that Hoff has shuffled off this mortal coil.
Gallo: Head North of Carsten and talk to her. You need to pull off a spot of William Tell action with your crossbow first and then she'll be ready to help. Hold down R1/RB to aim at the apples, and avoid hitting the performer.