Crocodile

The premise

In a chilly near-future Iceland, insurance investigators carry a "Recaller": a portable scanner that pulls a person's memory of an event and plays it as grainy video on a screen, prompted by sights, sounds and smells. Memories are admissible, routine evidence. Architect Mia, hiding a long-ago hit-and-run, kills to keep her past buried as one Recaller session leads investigator Shazia ever closer. The episode's nightmare is mental privacy collapsing: there is no longer a difference between what you witnessed and what others can extract, and the tech keeps reaching further, eventually reading the memories of a bystanding infant and even a guinea pig.

What the episode imagines

• 🧠❌Memory extraction tech
• 👁️❌Surveillance for insurance
• 👁️❌Privacy invasion

How close are we in 2026?

We cannot replay anyone's memories like the Recaller, but "reading" perception from brain activity has moved from stunt to fast-improving science. In May 2023, UT Austin's Jerry Tang and Alexander Huth published a "semantic decoder" in Nature Neuroscience that turns fMRI activity into a running text paraphrase of what a person hears, imagines saying, or watches in a silent film. Crucially, it only worked with willing subjects who trained it for hours and could defeat it just by counting backwards. That consent dependency is the opposite of the Recaller's coercive extraction.

Reconstructing pictures, not just gist, is the closer parallel. Japanese teams and labs worldwide now pair fMRI with Stable Diffusion to rebuild seen images; 2025 papers like Meta's Dynadiff decode images from continuously evolving fMRI. In 2023 Meta's FAIR lab showed MEG-based decoding producing a stream of (rough) images at roughly 250-millisecond delay, the first hint of real-time visual decoding. Reconstructions of dreamed or remembered scenes remain crude and semantic, not the cinematic playback Mia fears.

The surveillance anxiety is concrete enough that law is racing it. In 2021 Chile became the first country to enshrine "neurorights" in its constitution; in 2023 its Supreme Court ordered US headset-maker Emotiv to delete a senator's brain data. In the US, Colorado (2024) and California's SB 1223 (effective January 2025) amended their privacy acts to treat neural data as sensitive personal information, with Montana and Connecticut following.

Key real-world developments

• Brain-to-text from fMRI

  UT Austin's 2023 Nature Neuroscience semantic decoder turned fMRI signals into a continuous text paraphrase of perceived speech, imagined speech and watched video, but only for cooperating subjects who trained it and could block it at will.

• Near real-time image decoding

  Meta's FAIR lab (2023) used magnetoencephalography to reconstruct a stream of images from brain activity at about 250-millisecond delay, a 7x retrieval gain over linear decoders, though images lacked fine detail.

• Diffusion-model picture reconstruction

  Researchers in Japan and beyond now pair fMRI with Stable Diffusion to rebuild seen images; Meta's 2025 Dynadiff decodes images directly from continuously evolving fMRI recordings rather than static snapshots.

• Neural-data laws arrive

  Chile constitutionalized neurorights (2021) and its Supreme Court ordered Emotiv to delete brain data (2023); Colorado (2024) and California's SB 1223 (2025) classified neural data as sensitive personal information.

The verdict

Closer in spirit than in capability. Labs can already turn brain scans into the gist of what someone is seeing, hearing or imagining, and crude image reconstructions exist, exactly the "memory as evidence" premise. But every working system needs a cooperative subject, hours of personalized training, and a multimillion-dollar fMRI magnet, and the output is fuzzy semantics, not Mia's high-fidelity playback. There is no covert, portable Recaller, and consent remains a technical wall, not just a legal one. The fact that four-plus jurisdictions now legislate neural data shows the threat is taken seriously.

Sources

• Nature Neuroscience: Semantic reconstruction of continuous language from non-invasive brain recordings (2023)
• UT Austin News: Brain Activity Decoder Can Reveal Stories in People's Minds (2023)
• Meta AI: Toward a Real-Time Decoding of Images from Brain Activity (2023)
• KFF Health News: States Pass Privacy Laws To Protect Brain Data (2024)
• California Legislature: SB-1223 Consumer privacy: neural data (2024)
• PMC: Chilean Supreme Court ruling on the protection of brain activity (2024)

Reviewed and updated by the How Close to Black Mirror editorial team on 20 June 2026. Progress scores are reasoned editorial estimates based on the cited sources, not scientific measurements.