I could have sworn I got all the additional content and costumes, but apparently not.

After looking at the Change Logs for the past few updates, I can't isolate what it was that I missed.

Anyone know what scene this is? and a hint on how to get it started?

Please don't tell me the steps, just a hint. I like do these for myself without much assistance.

Thanks in advance

Not about the costumes, nor book of events. Go find  the robe guy in the haunted woods