Ep 5. The Darkness and the Light

Barry and the team are eager to catch Zoom once and for all, but they are hindered when a new villain, Dr. Light, arrives in town. Cisco deduces that Dr. Light is actually from Earth-2 and was sent to kill him by Zoom. Meanwhile, Barry struggles with his relationship with Patty and Joe discovers some startling truths about his past. As the team works to stop Dr. Light and uncover Zoom's next move, they also grapple with their own personal challenges and relationships. But when a shocking bad decision threatens to jeopardize everything they have fought for, they must rally together to face the darkness and overcome their own fears in order to protect their city and those they love.