[Answer] The Ghost Adventures crew conducted a two-part investigation in Alton, Illinois: one of the most haunted places in America. They found the pool at Mineral Springs Hotel teeming with dark energy and always reeking of what?

Step 1 : Introduction to the question " The Ghost Adventures crew conducted a two-part investigation in Alton, Illinois: one of the most haunted places in America. They found the pool at Mineral Springs Hotel teeming with dark energy and always reeking of what? "

...1. old roses 2. methane 3. chlorine 4. sulfur