With a burst of light and a "Vuyoing!" sound, Tiff suddenly vanished. Katie searched frantically to see if she could find anything explaining what this machine was and what it had done with her friend. Finally, in the drawers under the desk the machine was sitting on, she found some hastily labelled schematics, but before she could read them, there was another flash and Tiff was back.
"Tiff! Where were you?"
"I dunno, some boy's house", said Tiff. "Listen, the machine is some kind of teleporter! I changed the number and I wound up somewhere else, changed it again and now I'm back".
"You're close", said Katie, looking again at the schematics.