About Motive v. Opportunity
Motive v. Opportunity is a part of short story collection The 13 Problems written by Agatha Christie. It features Miss Marple as an amateur detective, along with her nephew Raymond West and her friend Sir Henry Clithering.
Mr Petherick tells his story, which has a legal background. A client of his, whom he calls “Simon Clode”, was a wealthy man who had one son who was killed in the First Word War. He left an orphaned daughter who in turn died when she was a child, leaving the old man bereft and grief-stricken. A brother of his had also recently died and his three children, Grace, Mary and George – all grown-up by the time of the story – came to live with Simon.
His will left his estate to these three in equal shares. Grace married but lived nearby with her husband, Philip. George found employment in a bank, while Mary stayed behind to care for Simon. The old man still pined for his granddaughter and found himself under the influence of an American Spiritualist, Mrs Eurydice Spragg, and her husband, Absalom. Mrs Spragg conducted many seances, in which Simon Clode contacted his granddaughter, and the Spraggs were virtually resident in the house.
Change of Will
Alarmed by this, Mr Petherick visited his client and then suggested to Grace’s husband, Philip, that a noted professor on the subject of spiritualism be invited to the house to witness the séances. This happened, with the result that the professor stated that the Spraggs were frauds. At hearing this, “Simon Clode” threw Philip out of the house in a fit of anger. The old man then fell ill and was near death. He instructed Petherick to attend him to draw up a new will leaving five thousand pounds to each of his nieces and nephews and the greater part to the Spraggs. As the old man lay in his bed, Petherick tried to dissuade Clode against the terms of the new will but to no avail. Two servants were summoned and instructed to fetch a pen and witness the new will, which Clode wrote out himself and gave to Petherick for safekeeping.
The Blank Will
After this part of the business had been concluded, Petherick went downstairs for tea and to help George Clode with some matters to do with the estate. During this period, Petherick left his overcoat where only Mrs Spragg could have gained access to the envelope with the will in it. Petherick took it to his office where he was soon visited by Mr Spragg, who was left alone with the will for a few moments. Two months later, Clode died. When the will was opened, the sheet was blank. Petherick’s problem was that Mrs Spragg had the opportunity to change the will, but the will was already in her favour, so she had the opportunity but no motive. George had the motive but no opportunity, as when he had access to the will Mr Petherick was present; thus George had motive but no opportunity.
Miss Marple again guesses the solution – the pen used to write out the will contained a solution of starch in water with a few drops of iodine in it (i.e. disappearing ink). Petherick confirms that Philip confessed as much in a guarded conversation they had had a month later. The house servants were told which pen to fetch for Simon Clode if it looked like he was going to be signing a legal form, and they complied. The three children gained their rightful inheritance.