Re'Kha made tiny holes at the bottom of both the paper cups and wound the thread through them, finalising the simple process. It was the simple telephone taught as a science experiment in sixth grade.
It seemed there existed a lot of backstory to them, but Re'Kha didn't receive them. Moreover, she wasn't bordered about learning about them in detail for the time being. She wished to get the Quest completed first.
Once they were connected, Re'Kha dropped one paper cup over the way, watching it fall slowly as she pulled the thread, adjusting its descent. She then placed it right next to the window of Chaya's room.
To ensure it would fly away or wobble around with the wind, Re'Kha had used the duct tape to form a circle around the cup. Moreover, this circle was double folded, to ensure there was a sticky layer on the outside too.