then I behaved exactly as I have told you.â
The detective sighed.
âWell, Mr Christensen,â he said, âthat will do for the moment, but I must ask you not to leave the house.â
The cripple nodded.
âI quite understand,â he said, and wheeling round in his chair, he passed out through the door that Jerry held open for him, into the hall beyond.
âNow,â said W.T. as the door closed. âI think weâll adjourn for the night.â
As might be imagined, the inspector and the red-headed policeman raised no objections and within ten minutes Jerry and his father were alone.
5 The Only Alternative
âWell,â said the old man, looking across at his son, âfound the murderer, Jerry?â
The boy grimaced. âItâs pretty obvious, isnât it?â
W.T. raised his eyebrows. âThat poor devil in the chair is responsible,â said Jerry. âLook here, Dad, this is how it happened â¦â
Hastily he gave a short outline of the theory he had formed in his brief sojourn in the drawing-room. âDid you notice that door?â he finished eagerly. âItâs always kept unlocked; the whole household use it. What could have been simpler than for the chap to nip in there, whip up the gun from the corner, fire from the table, and then bolt back again into the drawing-room and get out through the main door into the hall? Itâs as plain as print â heâs given himself away.â
W.T. sighed.
âJerry,â he said, âyou have a quick eye, a fertile imagination, and the gift of application, but youâll never make a detective â youâve no ground-work. Did you notice anything about that door besides the fact that it wasnât locked?â
âNo,â admitted Jerry, ânothing particular â why?â
The old detective produced his memo book and turned over the pages.
âHere,â he said at last â âhere it is. That door, Jerry, is barely twenty-six inches across â and our friend Mr Christensenâs chair is an exceptionally wide one. See his wheel-tracks on that sheet of newspaper on the floor down there â measure them for me.â
Jerry took the tape he proffered and went down on his hands and knees to obey him.
âTwenty-seven and a half inches,â he said at last.
W.T. nodded. âAnd thatâs without the wheel-hubs,â he said. âHe couldnât have got through your door, Jerry â so bang goes that little theory, my boy. No, Roger Christensenâs only way of committing that murder was to hurry out of the drawing-room as soon as he heard Crowther enter the hall, get past the man on the other side of the table, take the gun from the corner, kill him, and then double back out of the dining-room, taking care to avoid the body, which lay right across the inside of it â a very ticklish piece of work â and then hurry through the hall and back into the drawing-room, all before Kathreen arrived on the scene â she saw him coming out of the room, not going
into
it, remember. Pretty sharp work for a man hampered with a chair in three minutes, eh? The girl told us he had to âedgeâ his way through the drawing-room door as it was. By the way, youâll notice if you look that all the door-frames in the house are scratched where he passes in and out of them. No, Jerry, my boy, I donât think thatâs our man.â
Jerry sat back on his heels and looked at his father â his natural expression of faint bewilderment intensified.
âThen who â who ⦠?â he began.
W.T. nodded and passed his hands over his shaggy white head. âThatâs just the point. They all behave as if they were innocent, and yet each one is hiding something. Each has a motive for killing Crowther, and admits it freely. No sane person would dare to do that unless they felt safe. Letâs take them one at a time. Thereâs