Susan awoke suddenly to the sound of breaking glass. Her first thought was something supernatural, possibly even a monster, before she dismissed these thoughts as ridiculous. After all, monsters didn't come in through windows. Grabbing the poker for safety, she climbed out of bed and headed towards the source of the sound.
By the time she got there, the room was empty, the safe was cracked open, and the window was broken. Sighing, she turned to look at Twyla, who had come to investigate, and said, "Go back to sleep, I'll be back in a few minutes." She looked out the window and caught glimpse of a figure running away. Then, she carefully climbed out the window, down a drain pipe, and leapt to the cobblestones below.
She began to run after the dark figure, trying to get within earshot. The Voice was useful, but not if it couldn't be heard. She began to worry that she would lose him and considered stopping time, but after what had happened the last time, she decided against it.* Suddenly, she heard a howl, and the retreating figure was tackled by a much larger one. The larger shape retreated into an alley for a moment, then exited looking quite different. At least, Susan was fairly certain it was the same one. Whatever had entered had been large and hairy, and as she got closer, she saw that the new figure was petite, female, human, and decidedly nude. Despite herself, Susan felt a red blush creep into her cheeks. It's just the heat, she told herself. The figure looked up, it gave a start, then stepped back into the alley.
"Uh, City Watch, carry on," it said hastily, but Susan continued forward. After all, she though, he did steal from my house. Susan heard the rasping of cloth, the chink of metal, and then the guard exited the alley again, this time fully clothed. Susan walked over to the would-be thief, reached down, and grabbed the bag full of gold that her employers kept in their safe.
"What are you doing?" said the woman behind her. "Just retrieving what this man stole from me," replied Susan, turning around calmly. The guard looked at her for a moment, then nodded, and moved to cuff the criminal. Susan stared for a moment, shook herself, then turned to walk back to the house. "Stay out of trouble," she heard the guard call behind her as Susan turned the corner.
*Ankh Morpork had enough magical disturbances as it was. It had rained frogs (or at least something like frogs) the last time Susan had interfered by freezing time within the city.