Postdigital Gothic describes a mode of narrative and critical enquiry that evokes the unsettling nature of human and nonhuman actors interwoven within technological assemblages. This represents a turn away from the ‘Cybergothic’ fascination with the ghostly, immaterial aspects of digital media. Instead, Postdigital Gothic calls attention to hidden architecture undergirding the virtual. From sound and image compression formats to the secret algorithms that fuel social media, the digital realm is not an empty portal for ghosts, but rather a vault of manuscripts buried beneath familiar interfaces. The unspeakable manifests itself through the noise of computer glitches, compression artefacts and sonic disruptions. Those unwelcome disturbances signify our human entanglement with the nonhuman. This chapter begins and ends by highlighting cinematic examples of Postdigital Gothic narratives, first, in found footage horror, and then, in the computer screen horror movies Unfriended (2014) and Unfriended: Dark Web (2018). In addition to those readings of cinematic texts, a Postdigital Gothic interpretation of popular compression formats for music (MP3) and images (JPEG) suggests the usefulness of the Gothic as tool for understanding the interpretive work of machinic speech.