is my roof leaking 4

https://alpha-wiki.win/index.php/How_to_Tell_the_Real_Ceiling_Water_Stain_Cause_Before_Calling_a_Contractor

I noticed a dark stain spreading across the living room ceiling this morning, right after that heavy rain last night. It's right above the old chimney, and when I touched it, the plaster felt damp. Guess I need to get up there and see if there's a missing shingle or cracked flashing from that storm last month.