Ok here's what I got from watching BBAD--Apparently Kevin was called to the DR and from there told to go to the HOH room. When he opened the door he found a new door inside,inside that door was Pandora's Box. There was a card for him to read and it said something like he could give his housemated $10,000 if he was willing to stick his hand in the box.
Everyone else was outside,hanging out when all of a sudden it started raining money on them. They ran around scooping it up and Natalie ran to find Kevin so he could grab some also.
Well here's where I get fuzzy because I'm going by what Jeff and Natalies conversation about the event was so....Natalie says she found Kevin locked into the little room w/Pandora's Box and that he told her to find the key to let him out--She says she told everyone else to focus on grabbing the cash and she would look for the key and they could split the money with her. Jeff says he followed her and found out about the key and at that point figured the key was important so he started to hunt for it also.
Jeff found the key under some pillows (on the couch??) once he had the key he was able to let Kevin loose (there was something about him being handcuffed

)
Now since it rained money noone in the DR has told them anything about why it happened and has only told Natalie that they would have checks cut in the amount that each person found on Monday (yesterday) because accounting was closed for the weekend.
Jeff is going nuts wondering if there is more to the key. Natalie insists that there isn't though she has tried to get Jeff to give it to her.
I'm hoping there is more to the key and it will send the grubber Natalie home!