"I know you hate the sight of me," he said apologetically — and the tone was not wholly acting — "but I wish you would let me talk to your sister for just two minutes. You can stand outside the door with a stopwatch. Or come in, if you like, of course. There is nothing at all private in what I want to say to her. It's only that I am in charge of the investigations in this case, and it is my duty to see the seven people who were nearest the man last night. It will help me enormously if I can write them all off the slate tonight and start on fresh lines tomorrow. Don't you see? It's mere form but very helpful."

As he had hoped, this line of argument was a success. After a little hesitation the girl said, "Let me go and see if I can persuade her." Her report of the inspector's charms must have been a rose-coloured one, for she came back in less time than he had dared to hope and took him up to her sister's room, where he had an interview with a tearful woman who protested that she had not even noticed the man until he had fallen, and whose wet eyes regarded him continually with a dreadful curiosity. Her mouth was hidden behind a barricade of handkerchief which she kept pressed to it. Grant wished that she would take it down for a moment. He had a theory that mouths gave away more than eyes — certainly where women were concerned.

"Were you standing behind him when he fell?"

"Yes."

"And who was alongside him?"

She could not remember. No one was paying attention to anything but getting into the theatre, and in any case she never noticed people on the street.

"I'm sorry," she said shakily, when he was taking his departure. "I'd like to be of use if I could. I keep seeing that knife, and I'd do anything to have the man that did it arrested." And as Grant went out he dismissed her from his mind.