If necessary alone - V. M. Knox

Britain 1941. Still reeling from the greatest loss of his life, the Reverend Major Clement Wisdom is called on again to serve his nation in its time of need. Under the cover of taking up a new parish in far northern Scotland, Clement is sent to the remote village of Huna, in Caithness, to locate a possible enemy agent who is sending out encrypted radio messages.
Arriving in the depths of winter, Clement quickly finds it isn't only the temperature that is unnervingly cold. Perched on the edge of Great Britain, the isolated community is wary of strangers. Struggling to gain trust from the locals and where even his assigned Government contact, the local Postmistress, is antagonistic, he becomes entangled in a web of silence.