Answer:
Examining the house more closely
Step-by-step explanation:
This answer is quite explicit in the text. When the narrator speaks "Shaking what must have been a dream" he is referring to that he was dreaming and woke up. When the narrator speaks "I scanned the building more closely" the word "escaneei" in this passage refers to "scanned ", this shows that what the author is doing at that moment is "Examining the house more closely" .