How well do you know the one you love?
Why it is hard sci-fi
A near-future Iowa where climate failure has driven a long-term off-world relocation program. A married couple receives a notice that the husband has been selected for a mandatory two-year tour on an orbital habitat, and that a synthetic copy will replace him at home for the duration. The film is rigorous about the procedural shape. Selection, training, behavioural sampling, and the synthetic deployment are all shown.
Science inside it
Behavioural cloning from a partner-relationship corpus, synthetic biology for human-passing replacements, off-world relocation under a working climate-collapse scenario, and the operational mechanism by which a marriage is sampled by a third party for replication.
Spoiler alert
The film reveals partway through that Junior is already the synthetic. Hen has been relating to a copy for an extended period. The originals tour has already happened in another sense. The film commits to the consequence rather than treating it as a twist.