The prisoner was plucked from a free-living existence and plunged, without trial, into a cell from which it will never leave. It will be provided with food but will have to cater to the needs of its jailer, bereft of its own independence. And yet, this apparent injustice will go unchallenged. No liberal hackles will be raised and no bags of angry letters from Amnesty International will flood the oppressor’s mailbox.

For this event did not occur in the world of autocrats and tyrants, but in that of a microscope slide. The captor measures less than a thirtieth of a millimetre across and its captive is smaller still. Even so, their relationship is a snapshot of one of the most important