Pentiment

During Act 2, you need to gather enough evidence on Hanna (owner of the Golden Hand inn) to be able to accuse her.

Once you get to 24 June, you can investigate:

• Talk to Hanna in the Golden Hand
• You can suggest that she’d want Otto out of the way to protect the inn
• There’s a persuasion attempt here, but I failed it
• Go to forest to look for flowers. Examine all the flowers there, including by the salt mine, Smokey’s house and waterfall.
• Andreas will suggest looking deeper in the forest. You can now access a new area to the right of the Shrine of St Satia.
• Go through and you’ll have to do a section exploring the ruins
• As you escape, you’ll catch Lenhardt and Hanna and get some juicy details of their affair
• Afterwards at Compline (20.00) speak to Hanna and bring up her affair
• There’s a persuasion attempt here, which again I failed. Tell her Niko doesn’t know if you want to do better than me.

I think that's all you need to do, but there are some other things that might help:

• On 23 June (St John’s eve) talk to Else at the Muller house
• on 24 June at 18.00 (Vespers) talk to Killian in the pub. You’ll discover a note.
• Talk to Niko about his wife as well. There’s a persuasion attempt here, but (surprise surprise) I failed it
• You can also talk to Lernhardt (the miller) and tell him you know
• Choose to buy a round of drinks for everyone. Play cards and they’ll discuss Hanna going to the Rathaus a lot
• When talking to the doctors upstairs, you should get the opportunity to note that Hanna had the opportunity to commit the murder

When you get to the town square at Vespers (19.00), you’ll be being questioned by Peter. You should be able to accuse Hanna and the achievement will pop.