For the " Crisis on Earth-X " crossover event, only Cavanagh returned to play Thawne; Letscher confirmed on his Twitter account that he was not asked to return. Letscher was similarly not contacted to reprise the role for the fifth season of The Flash, a decision showrunner Todd Helbing credited for Cavanagh's Thawne making sense in a "weird, time travel way" and being applicable to the season's "legacy" theme. Cavanagh would later be reported to appear as Thawne in the " Crisis on Infinite Earths " crossover event, which aligned with the allusion in the first season of The Flash that Thawne would have a role in a potential adaptation of Marv Wolfman 's and George Pérez 's 1985 comic book storyline of the same name. However, Thawne ultimately did not feature in the crossover. In an interview with TVLine, executive producer Marc Guggenheim attributed the decision of not having Thawne included to the newspaper headlines hinting at his involvement in the show's first season having been written by showrunners, like Kreisberg, no longer involved in the shows or the crossover, plus Thawne's already prominent presences in previous crossovers like " Elseworlds ", citing Thawne's exclusion as a "hard story choice" to make given his fondness for the character.