은애는 5년 동안 개발한 노인 특화 AI 프로그램 ‘조이’의 데모 데이를 마치고 강수토건으로부터 투자 제안을 받는다. 한편 뉴욕에서 젊은 건축가상까지 받은 전도유망한 건축사 결, 강수토건 회장인 할아버지에게 엑스레이 사진을 받는다.
Yeon-ja is happy with her accomplished family. Her husband is an executive director, her son a professor-to-be, and her daughter a medical student. But she worries about her second daughter, Eun-ae. After presenting "Joy," a senior-focused AI program she developed over five years, Eun-ae receives an investment offer from Kangsu Construction. Meanwhile, Gyeol, a rising architect who won a Young Architect Award in New York, receives an X-ray from his grandfather, the chairman of Kangsu Group.