Answer
Call the sellers immediately and let them know you won’t be coming by.
Step-by-step explanation:
After Mike and Marge got to the showing with Elaine, it is very possible that Mike must have made a change of mind because he wasn't impressed with what he has seen from the outside.
The real estate agent would then have to contact the sellers immediately and let them know you won’t be coming by since the business has no likelihood of being continued.