Weird science fiction is a subcategory of science fiction that adapts horror and supernatural elements, often with a focus on awe- and fear-inspiring monsters. In this paper, I argue for a shift from exploring the generic qualities of weirdness to weirdness as a mode inherent to the ideologies of science fiction. As a mode, the weird’s stance seems to be one of entanglement, porosity, and multispecies becoming, a stance in opposition to the commonly held belief that science-fiction works are a bastion of humanity’s progress ever onwards and upwards. In working out our relationship to progress, a supposedly natural and inevitable forever-fantasy that views the environment as something separate from and with less agency than humans, we come to the weird: we come to progress’s failure – how it fails, why it fails, and where to go from here. The three primary texts analyzed in this paper, Jack London’s “The Red One,” J. G. Ballard’s “The Terminal Beach,” and Jeff VanderMeer’s Southern Reach trilogy, all occupy an important place historically in the science fiction genre, but they also disrupt the ideologies of progress that dominate much science fiction literature. These works do this through the underlying, shadowy presence of weirdness that reveal both humans' inherent interconnectedness and limited perceptions of the world.