Recursion

Helena demonstrates she knows Barry, referencing his feelings for his family. She tells him about building the chair and says his apartment isn't safe—Slade knows where it is. She tells him about her years in hiding. When the timelines converged, Slade gained enough memories of the chair to rebuild it himself, and Helena came to New York to find him. She brings Barry to the warehouse where she’s been living and rebuilding her own chair.

She explains that if Barry storms the hotel, his team will kill Slade, and the media will report that Slade was distributing a virus responsible for FMS. Government agents will take the remaining pieces of the chair and start rebuilding it, leading to further confusion and destruction. She knows this because it has already happened—she has come from another timeline where she and Barry were working together. She proposes that they take over Slade’s lab and destroy all the equipment and software, making the chair impossible to rebuild.

Barry stays at Helena’s warehouse that night. Helena tells Barry that his future self taught her how to shoot, and she is prepared to give her life to destroy the chair.