Eric Ambler 
Skytip [PDF ebook] 

Peter Ackland is ordered to rest by his Doctor. He travels to Cornwall and is greeted by Henry Braddock at the door of a cottage below the ’skytip‘. Braddock has a revolver in his pocket. Ackland also comes across Nathan Murrison and his valet, who divide their time between exploring the ’skytip‘ and propping up the bar of the Green Dragon; a charming young lady who, on behalf of a Member of Parliament, tries her hand at burglary; other less charming characters who try their hand at blackmail; and a stage that is all set for murder.