Impulse #21 was published by DC Comics on January 1, 1997, as part of a series that began in 1995. Jason Hernandez-Rosenblatt and Mark Waid write, and art comes from Craig Rousseau, Humberto Ramos and Tom McCraw. This 36-page issue features Barry Allen, Wally West, Saturn Girl, Cosmic Boy and Bart Allen, among 9 characters cataloged on VerseDB.