Barry Allen and the team managed to stabilize Dr. Stein in CW's "The Flash" Season 2 Episode 4.
Season 2 Episode 4 is entitled "The Fury of Firestorm." As per Collider, the episode saw Allen's team put Dr. Stein in a stable condition; however, it was only for a short span of time. The team made an attempt to look for a feasible partner for the Firestorm matrix and found a couple of possible candidates, the scientist Henry Hewitt and the previous high school football star Jefferson Jackson.
Hewitt failed to merge with Dr. Stein, so left angrily, without the knowledge that he had been connected to the matrix. Jackson refused at first, but eventually agreed after witnessing Hewitt's new abilities. After Jackson's successful merge with Dr. Stein, the new Firestorm joined Allen to take down Hewitt, who got madder and burned himself and lost his abilities.
Dr. Wells broke into Mercury Labs and stole an unrecognizable device. A humanoid shark monster sent by Zoom attacked Allen, but was incapacitated by the device Dr. Wells stole. Iris also surprised Joe while Allen and Patty grew closer.
Meanwhile, Season 2 Episode 5 is entitled "The Darkness and the Light." According to Spoilers Guide, the episode would see Allen meet and capture a new breacher, Dr. Light, who had come through the portal. The publication also mentioned that Jay Garrick would inform Allen that Dr. Light had not been a threat on Earth 2. But then, The Flash would be blinded by Dr. Light and would receive information about Zoom.
"The Flash" Season 2 Episode 4 "The Fury of Firestorm" aired on Oct. 27 while Episode 5 "The Darkness and the Light" airs on Nov. 3.