to the object of my visit。〃
〃Your little idea？〃
〃Yes； my little idea。〃 Poirot smiled。 〃First of all； Monsieur； I should like to interview once more the maid； Ada Mason。 She is here？〃
〃Yes； she's here。〃
〃Ah！〃
Van Aldin looked at him curiously。 He rang the bell； and a messenger was dispatched to find Mason。
Poirot greeted her with his usual politeness； which was never without effect on that particular class。
〃Good afternoon； Mademoiselle；〃 he said cheerfully。 〃Be seated； will you not； if Monsieur permits。〃
〃Yes； yes； sit down； my girl；〃 said Van Aldin。
〃Thank you； sir；〃 said Mason primly； and she sat down on the extreme edge of a chair。 She looked bonier and more acid than ever。
〃I have e to ask you yet more questions；〃 said Poirot。 〃We must get to the bottom of this affair。 Alan in the train。 You have been shown the te de la Roche。 You say that it is possible he was the man； but you are not sure。〃
〃As I told you； sir； I never saw the gentleman's face。 That is what makes it so difficult。〃
Poirot beamed and nodded。
〃Precisely； exactly。 I prehend well the difficulty。 Now； Mademoiselle； you have been in the service of Madame Kettering two months； you say。 During that time； how often did you see your master？〃
Mason reflected a minute or two； and then said：
〃Only twice； sir。〃
〃And was that near to； or far away？〃
〃Well once； sir； he came to Curzon Street。 I was upstairs； and I looked over the banisters and saw him in the hall below。 I was a bit curious like； you understand； knowing the way things … er … were。〃 Mason finished up with her discreet cough。
〃And the other time？〃
〃I was in the Park； sir； with Annie … one of the housemaids； sir； and she