While home, Dr. Wells receives a threatening call from an unidentified person before having to use super speed to move out of the way of his glass ceiling shattering around him. Wells informs Barry and the team that the caller was Hartley Rathaway, a former protégé. Hartley begins attacking his family's business with sonic blasts, and when Barry arrives to stop him Hartley reveals that he knows the secret Dr. Wells is hiding. Dr. Wells reveals that Hartley warned him that the particle accelerator could explode ahead of time, but Wells chose to risk it for the potential rewards