A slightly different sort of story, but still one that deals with what's behind the door.
I'm also a real estate investor, and last fall went on an "Investor's Bus Tour" of properties in Baltimore, Maryland. The person putting on the tour had put options on about 12 properties in and around Baltimore. All needed some degree of rehab, and the houses ranged from old mansions to rowhouses. And they ranged from nice to not-so-nice neighborhoods.
We each received a notebook, with a fact sheet on each property. The sheet contained the purchase price of the property, and an estimate of the amount of repairs. In Baltimore, a total gut of a rowhouse runs roughly $70,000.
It soon became apparent that our guide hadn't pre-visited all the properties. We couldn't get into one or two. But our guide was prepared with flashlights, a drill with screwdriver bits (to unscrew the screws on boarded-up buildings, etc.
So, anyhow, about halfway through the tour, the bus is heading to the next house, down a street of what clearly had once been a solid middle-class neighborhood, but had now declined somewhat. Some houses were boarded up. Others were occupied, but clearly weren't in great shape. We pull up to the next house on our list. The repair estimate was, I think, about $35,000. That'd suggest that it needed substantial work, but wasn't really a gut job. The house is boarded up, so our guide gets out his power drill with screwdriver bits, and proceeds to unscrew the screws holding the boards blocking the door. He gets the boards unscrewed and with a crowbar pulls the boards off, then crowbar-opens the door.
And we look in...and through. The entire back of the building is gone; we can see the houses in the block behind. Worse, most of the roof is gone. And worse, most of the floors are gone. There's a couch that had originally been on the upper floor. When that floor had collapsed (probably from water/rain after the roof collapsed), the couch--the whole thing--had crashed through and was hanging/dangling from the second floor into the first floor. And the walls of the adjoining rowhouses are bulging maybe a foot or two into the space previously occupied by the rowhouse we were looking at.
Our guide didn't bat an eye. He just said something like, "Well, it looks like it needs some work." And on we went to the next property.
Moral of the story: You never know what lies beyond the front door!