Reeya Rai has joined her archaeologist parents on an excavation of an underground city in Turkey. There she learns the legend of an Indian inventor and his water clock cup. She also learns that Turkey is an earthquake hot spot. Worried that warning signals won’t make it to the archaeologists working in the underground city, Reeya builds a homemade seismograph. It's designed to indicate an oncoming earthquake for those working underground. Will Reeya’s invention keep her parents and others safe, and will they ever find the legendary cup? Part of the Reeya Rai: Adventurous Inventor series.