While there is no episode titled " There's Something About Mary " in Season 15, the episode and " There's Something About Mary " (S12E21) are both pivotal late-season entries that deal with Mary Winchester’s legacy or her immediate family. Review of " Galaxy Brain " (Season 15, Episode 12)
This episode serves as a "cleanup" of lingering storylines as the series heads toward its finale. Critics generally praised its ambitious scope, specifically God's "minimalist" approach to destroying the multiverse.