"Circle" is a rollercoaster ride that never stops and if this is a result of its short duration, thank goodness Dramaland decided to try it. In 2017, Woo-jin and Jeong-yeon clear up some misunderstandings and unearth a disturbing secret about the suicide victims. In 2037, Joon-hyeok's suspicions are proven right, leaving him and Ho-soo struggling with their past and identities.
Bluebird sounds very nice, but blue bug not so much. That being said, the headaches and nosebleeds in the 2017 victims have been pointing to a medical condition and so the bug is not such a huge surprise. Whether it is alien or synthetic, whether originally a weapon or a cure, it is clearly a precursor to the care chip. The big questions are, are the students willing participants to a clinical trial or not and is their death intended or a side-effect?