NOTE TO Franz: All of this information here in the 'Main Quest' lore pages is not known by the NPCs unless they are specifically mentioned to know about a piece of information.
Getting into @Bates Mansion in the city of @Tarant is you first challenge. Possible solutions include:
Fighting your way in
Convincing the Captain of Bates Guard (@Reuben Marshall) that you are an old friend
Prowling and Lockpicking your way through the front entrance of @Bates Mansion
Protecting the @Bates Engine Factory for the night
Talking with @Cedric Appleby (who asks you to blow up @Bates Engine Factory) and then turning him in
Talking with @Cedric Appleby (who ask you to blow up @Bates Engine Factory) and then blowing it up. He will then give you 300 gold, he will then give you servants clothing and ask you to find incriminating evidence on @Gilbert Bates. You may need to find more servants clothing for any followers you have.
Talking with @Cedric Appleby and not agreeing to blow up the factory and instead offer to expose him. He will then give you a key to the Mausoleum which has a secret passage to the @Bates Mansion in @Tarant (however this is full of traps). Once there you will find servant’s uniforms in chests.
Once you are in, breaking into the back room to get any incriminating evidence can be tricky. Without violence, it requires lockpick skills and extreme timing or lockpicking and prowling.
Note – As long as you have talked with @Cedric Appleby before joining @Gilbert Bates side, you can still expose @Gilbert Bates as a fraud after dealing with @Gilbert Bates. You should wait for a while as it makes completing further quests more difficult. When you give it to @Cedric Appleby, he will pay you 500 gold. He can be pressured into increasing this to 700 gold depending on your skills.
After you show @Gilbert Bates the ring, he confirms that it belongs to him and reveals the story of his past. He explains that the "gnome" who gave you the ring at the crash site was actually Stennar Rock Cutter, a dwarf from the @Black Mountain Clan, who had been disguised as a gnome. @Gilbert Bates recounts how, as a young man, he was fascinated with technology and deeply admired the dwarves' work, but was treated as a child by them despite being an adult by @Human standards. He discovered a @Dwarf steam engine, modified it to pump flooded mines, and presented his invention to the dwarves, only to be rejected again. This rejection led him to sell his invention to a human mining company, which then claimed he was the inventor, a fact he could not correct without undermining his own success. He later learned that the @Black Mountain Clan had vanished, and attempts to find them ended when shadowy figures warned him to stop investigating. He also mentions that the ring was originally ordered by his father and given to Stennar when he was younger. Bates then asks you to help him investigate what happened to the @Black Mountain Clan, marking the Black Mountain Mines on your map.