six o’clock
Poirot puffed at his tiny cigarette , his eyes fixed on the ceiling . `` They arranged a plan to throw suspicion on John Cavendish , by buying strychnine at the village chemist 's , and signing the register in his hand-writing . `` On Monday Mrs. Inglethorp will take the last dose of her medicine . On Monday , therefore , at six o'clock , Alfred Inglethorp arranges to be seen by a number of people at a spot far removed from the village . Miss Howard has previously made up a cock and bull story about him and Mrs. Raikes to account for his holding his tongue afterwards . At six o'clock , Miss Howard , disguised as Alfred Inglethorp , enters the chemist 's shop , with her story about a dog , obtains the strychnine , and writes the name of Alfred Inglethorp in John 's handwriting , which she had previously studied carefully . `` But , as it will never do if John , too , can prove an alibi , she writes him an anonymous note -- still copying his hand-writing -- which takes him to a remote spot where it is exceedingly unlikely that anyone will see him .