The killer was... the chauffeur!

SIR Arthur’s killer was HAROLD, the disgruntled chauffeur, soon to be turfed out of his grace-and-favour cottage after a lifetime’s loyal service.

As deduced by Inspector Morris, Sir Arthur ate the poisoned cake while at his desk then rose and took an almanac from the bookcase.

The cyanide took effect before he could get back to his desk to write down the name of the killer.

He ripped six flags from the almanac, leaving a ‘capital!’ clue to help others identify his killer.

The first letter of each country’s capital city forms an anagram of Harold’s name – Ankara, Dublin, Oslo, Reykjavik, Lima, Havana.

Confirming the inspector’s theory, he and PC Briggs search the Rolls-Royce driven by the chauffeur.

In the glove compartment, they find a cake recipe with Harold’s fingerprints. Confronted with the evidence, the chauffeur confesses.

He had baked the cyanide cake then taken it in to Sir Arthur when the house was empty. Case solved!