Ep 4. The Girl in the Secret Room

In Phi-Brain season 1 episode 4, titled "The Girl in the Secret Room," Kaito and the rest of the Phi-Brain team are invited to a mysterious mansion to solve a puzzle. Upon arriving, they meet the eccentric puzzle master known as Baron Kaidou, who presents them with a challenge. However, things quickly take a sinister turn when they discover a secret room containing a girl named Raetsel, who has been trapped inside for years.

Raetsel is a master puzzle solver in her own right, and with the help of Kaito and the team, they must unravel the mysteries of the mansion and free her from her isolation. As they delve deeper into the puzzles, they realize that there is more to this challenge than meets the eye.

Meanwhile, Kaito is also dealing with his own personal struggles as he tries to come to terms with his past and his relationship with his childhood friend and rival, Rook. As the tension builds, Kaito must rely on his friends and his puzzle-solving skills to overcome the challenges and save Raetsel.

With intense puzzles, complex characters, and a thrilling storyline, "The Girl in the Secret Room" is an exciting installment in the Phi-Brain series that will leave viewers on the edge of their seats.