Need help remembering title of short-lived mystery series

There was this show that was only on for, I don't know, maybe a few episodes, and I've been trying to remember what it was called - even going through IMDB using their "keywords" feature, but have come up with nothing.

What I remember about it - though it may not be correct:

It aired on ABC sometime in the early 2000s. It was about a young woman who came to this town and was lodging in this old, big house. The landlady told her to not go to the upstairs, for some mysterious reason, but as soon as the landlady was out of the house, the young woman did go upstairs. It wasn't out of curiosity; she had come there - to this town, to this particular house - on purpose to investigate something that had happened there in the past years before, to a family member.

I think the young woman was using a false name in order to deceive people about her real identity because she didn't want them to know who she actually was. And she might've been reporting to someone by phone, keeping them appraised on whether she found anything or not, because she almost got caught talking on the landlady's phone...

And that's about all I can recall. Can anybody help me with the name of this show?