This week, the cast hosts the Empty Head Avengers Competition to find out who's the smartest and the most clueless among Song Ji Hyo, Yang Se Chan, Choi Daniel, and Ji Ye Eun. Meanwhile, the remaining four Brainiacs will place bets using special summer-themed betting money. It's a fierce contest within teams, where every point counts. Only the top scorers will boost their odds of escaping the final penalty. How will the Empty Heads rank?