|For alternate versions of Chase Stein, see Chase Stein's Character Hub|
- "The two most powerful forces in life are invisible. The first is love. The second is time."
- ―Chase Stein[src]
Chase Stein was a former member of the Runaways who dedicated three years of his life perfecting a time-travelling system in an attempt to go into the past and prevent Gert Yorkes, the love of his life, from dying at the hands of Morgan le Fay. With the assistance of alternate counterparts of the Runaways who he protected from Alex Wilder, he was able to complete his mission, dying in place of Yorkes and ensuring her survival.
Traveling to the Past
Consumed with grief after the death of his girlfriend Gert Yorkes, Stein worked on a way to save her. Using help from Alex Wilder and the Abstract, he developed a time machine that would send him into the past, at the time of the Battle at the Hostel, so that he could take Yorkes' place while facing Morgan le Fay, and thus prevent her from dying. Over the years, Stein came across Victor Mancha, which caused him to get a scar on his face.
Before his mission, however, Stein had to chase Wilder through the past. Indeed, due to a bomb having been placed in his office, Wilder had decided to return into the past and eliminate the Runaways. In order to protect them, Stein went after him, and arrived in time to assist Nico Minoru while she was attacked by Wilder. After Wilder escaped, Stein explained to Minoru who he was, and urged her to reassemble her friends.
Stein thus met with the other Runaways, including the more peaceful version of Alex Wilder, but avoiding any form of contact with his own former self. Stein warned the Runaways that the evil Wilder could try to attack their loved ones, prompting the group to check on Julie, Karolina Dean's girlfriend. They arrived in time to stop Wilder from further hunting her, but Stein got a moment of distraction that enabled Wilder to escape by leaping through time again.
Stein used his time machine to track down Wilder to the time before the future Runaways witnessed the Rite of Blood, which had eventually caused them to team up. He thus gave the Runaways their own time machines and they followed Wilder through time, arriving at the past Atlas Academy. Dispatching through the school to monitor their past selves, Stein came across Yorkes, and could not help but go and talk to her, expressing utter affection which surprised her since she did not know about her future relationship with Stein.
Stein then resumed his chase of Wilder, who the Runaways were able to capture thanks to Minoru. They brought him to the school's gym, where Stein urged the other Wilder to return into his own time, since it was better to avoid interactions with his future self. Upon agreeing, Stein shared a hug with this version of Wilder before setting up his time machine and sending him back to his time.
Sten then explained to the other Runaways that he would make one last leap into the past and go back to the time of the battle against le Fay to save Yorkes. He was surprised when the others insisted to go with him, even though Wilder warned them that such a drastic change would alter the timeline to the point that their current versions would be erased. Stein admitted that this was true, but also explained that there was a possibility that the Runaways would take a similar path that they had, but this time with Yorkes by their side.
Accompanied by the Runaways and Alex Wilder, Stein leaped through time and arrived in the Hostel, hiding from PRIDE and the current counterparts of the Runaways. He then explained that he would take Gert Yorkes' place in closing the circle of salt blocking Morgan le Fay, thus ensuring her survival. While they discussed, however, Wilder was able to get away from them, but Stein decided to carry on his plan before catching him again.
As the attack of the Coven began, Stein quietly approached his past self and knocked him unconscious to take the Fistigons from him. He then went to see Yorkes as she was on the verge of collecting the salt, and warned her that she would die if she went to confront le Fay by herself, which he wanted to avoid. He thus instructed Yorkes to remain behind before going to confront le Fay, accusing her of being one of the many adults that spoiled the youth years of the teenagers.
Using a dispenser attached to his shoe, Stein began to draw the circle of salt, all the while distracting le Fay by speaking to her. He was attacked by le Fay, but protected by Nico Minoru before she was incapacitated by the enchantress. Then, much to Stein's horror, Yorkes appeared and confronted le Fay as well, but the witch projected her against a wall, knocking her out. Stein attacked le Fay with the Fistigons, but she deflected the blasts, and then violently propelled glass shards at him, mortally wounding him.
Nevertheless, before dying, Stein was able to close the circle, thus blocking le Fay and enabling Tina Minoru to banish her back to the Dark Dimension. Stein's body was then watched over by Yorkes and the other Runaways, who believed that their friend had died in battle. However, the current Stein then regained consciousness and joined his friends, much to their surprise since they thought he was dead, while the future Stein's body vanished due to the timeline having been successfully altered.
Stein's defining characteristic was his sorrow of having lost Gert Yorkes during the Battle at the Hostel, which caused him to become increasingly reclusive while trying to find a way to revert her death, leading him to create a time machine. He therefore appeared much more melancholic and mature than he had been in the past, never losing focus on his purpose and accusing adults like Morgan le Fay of having stolen his teenage years because of their evil actions. He also has a willingness to protect others, as he demonstrated when chasing Alex Wilder to prevent him from killing the Runaways. In spite of his grief, Stein at times retained some brighter aspects of his former personality, for instance expressing pride when complimented about the development of his time machine.
- Expert Engineer: Stein was an extremely talented engineer, a skill that he had acquired from his teenage years. With help from Alex Wilder and the Abstract, he was even able to build a theory of time travel and to develop a time machine which would enable him to jump into the past.
- Time Machine: Stein developed a time machine with help from Alex Wilder and the Abstract as a way to save Gert Yorkes from death. He successfully used the time machine to jump into the past, and was even able to give the Runaways several versions of the device so they could come with him through time.
- Gert Yorkes - Love Interest
- Chase Stein