This next part is pretty straightforward. I don’t think you have any choices. Just head down the stairs and step on all three buttons so Ida can get to the fourth button.
The fourth button will lower Ida down so she can continue along the path.
When you get to this part, turn the knob until it gives you a clear path to go down.
Continue along to this really cool mirror part. The idea is to pay attention to the reflection. Use the slider to fill in the gap in the mirror, then tap to the left so Ida can cross. Then head down the ladder.
Talk to this guy again, then continue down all the stairs.
Again, you don’t really have any choice here. Every time you walk, the stairs will drop a bit so you can descend deeper.
When you reach the crypt, you’ll put the red flower on the grave to complete the chapter.