Sadie stalks. If she is playing in one room while you are in another room, get her attention and look at her in some funny way. She will stop; she will look in your direction; she will slowly come towards you, then stop, jump, and give you a loud bark. It looks like this:
I wanted to capture her stalking in some unnerving sort of way. To get that effect I decided to use slow-sync flash mode. Slow-sync mode allows you to let in more light so that your backgrounds look more natural and not dark. But this also means your exposure time may be longer, so your subject may look smeared in the image. This is because the flash fires when the shutter first opens. While the shutter remains open if the exposure is long and the subject moves during the remainder of the exposure, the subject will appear blurry or smeared.
To switch to slow-sync mode on the Nikon, press the button with the bolt icon (usually located to the left and below the pop-up flash), and while holding that button down, turn the rear dial until you see the word "SLOW" in the top LCD panel.
I set the ISO to 800 since I was indoors, but I guessed the exposure would be long, but no idea how long. The exposure time ended up being 1.3 seconds. You can see the slow-sync effects: the hallway behind her is overexposed because of the lights in the kitchen, there is a distinct image of her when the flash fired, and there's also a ghostly blur as she walked towards me after the flash fired and before the shutter closed. I cropped and tilted the photo, then used a Lightroom develop preset to get an eerie look.