Life for Agnes Turner in her retirement is dull and uneventful.

That is until she spots her mousy neighbour Amy Horrocks fleeing along the road in terror. When Agnes takes her in, Amy sobs out her distress: she is in fear of her life, harbouring a dark secret for which she is being blackmailed.

Amy turns to Agnes for help, and Agnes, eternally supportive in the face of injustice, deals with the situation in her own, inimitable way.