While on holiday Peter and Debbie befriend Elsa: a lusty, Trump-loving widow from Denver, USA. She’s less than woke but kind of wonderful, so they agree to stay in touch - because no one ever really does, do they?
When Elsa invites herself to stay with the family a few months later, they decide to look her up online. But it’s too late: on learning the truth about Elsa Jean Krakowski, the deadly danger is already on a flight to London! What began as a casual holiday friendship is suddenly a threat to all their lives.
Peter and Debbie now face the ultimate challenge of the modern world - how do you protect all that you love from mortal peril without seeming a bit impolite?