A Victorian explorer-cum-naturalist, William Adamson (Rylance), returned from the Amazon in financial straits, arrives at the country estate of his patron, amateur entomologist Harald Alabaster (Kemp), who not only lends a surprisingly sympathetic ear to Adamson's interest in Darwin's theories on natural selection, but even looks kindly on the scientist's courtship of his daughter Eugenia (Kensit). Soon after their marriage, the newcomer has reason to feel unease: Alabaster's boorish son Edgar (Henshall) openly considers him too low-born for his sister, while Eugenia veers confusingly between brazen sexual passion and lengthy periods of locking him out of her boudoir. Happily, however, Adamson has an ally in Matty Crompton (Scott Thomas), a likewise impoverished dependant of the Alabasters, who shares his interest in insects and the discoveries of the age. Haas's intriguing adaptation of a novella by AS Byatt is not your average period drama. For one thing, the costumes, designs, music and camerawork steer clear of naturalism, highlighting both the modernity of the approach and the notion of humans as creatures to be observed dispassionately. Despite some uneven pacing and variability in performance, this is a work of clarity, ambition and intelligence.