Donald, not realising what he did, picked up the female vial. He brought it to Jenny, but thinking it weird, that he brought her drink in a vial, she refused it and he decided to have it. After sitting down next to Jenny and taking a tiny sip to see how it tasted, he found it horrible, and actually threw the vial. Coincidentally, Mary was standing right next to where the puddle accumulated and she began to lap it up.
Mary knew that Donald would not change enough to notice, from drinking so little, so she sat and waited as Donald and Jenny went upstairs. Waiting for the changes to begin, she could hear them begin to make out in her room. Soon enough, she turned almost completely back into her human form, with the exception of her tail. But that, she took care of after she put the vial back into the box and it filled back up.
Putting it back in for the time being and realizing that she wouldn't want to try some of these vials on herself, untill she was sure about how they affected the person, she decided to make her betraying boyfriend and her backstabbing friend her guinea pigs. Taking a good look through the box, she decided that she was going to have fun with those two.
She locked the front and back doors, got a broom handle, and went upstairs. Once she got to her room, she opened the door only a slight crack, that way she could run in and knock them out before they knew what hit them. Barging through the door at lightning speed, she cracked Donald over the head first, since he was on top. (From this point on, call him Don. Donald is a horrible name.)With Don knocked out and pinning Jenny down, it only took a smile and a quick swing to take her out, too.
Mary decided to take Don's keys and hide both her key and Don's key. She also unplugged all the phones and hid the phone cords along with the computer cords, so there was no way of getting a message out. Finally, she shut all the windows, grabbed the box of vials, some rope from the cellar, and went to go have some fun, experimenting on her new guinea pigs.