The Undetected By GEORGE O. SMITH Illustrated by FINLAY [Transcriber's Note: This etext was produced from Galaxy Science Fiction December 1959. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] Nothing can possibly be more baffling than a crime in a sealed room ... but what if the investigator happens to have an open mind? I I took a quick look around the apartment, even though I already knew what I had to know. Gordon Andrews had been slain in his sleep by the quick thrust of some rapierlike instrument. There was no sign of any struggle. The wall safe stood with its door open and its contents missing. Every door and window was closed, locked, burglar-bugged, and non-openable from the inside; the front door had been forced by the police. Furthermore, it had been raining in wind-whipped torrents for hours, yet there was no trace of moisture on any of the floors. Of course no one had heard a sound, and naturally there were no fingerprints. Police Chief Weston spied me and snapped, "What do you make of it, Schnell?" I shrugged and said, "Completely sealed room." "Got any ideas?" he demanded. I had a lot of ideas, but I was not going to express myself without a lot of stark evidence. I do not yearn to have the prefix "ex-" installed in front of my title of Captain of Detectives. I'm much too young to be retired. So instead of trying to explain, I said, "The _modus operandi_ is--" Chief Weston snorted, "Schnell, there isn't a clue in the whole damned building, and yet you stand there and yap about _modus operandi_?" "That's the point, Chief. The cluelessness is itself the _modus operandi_ that points to--" "You talk as if we had a whole file of unsolved, clueless, sealed-room homicides!" "Chief," I said, "a true 'perfect crime' would be one in which no clue existed, including the fact of the crime itself--except those clues that were deliberately planned by the perpetrator for some purpose of his own." * * * * * He glowered at me. "What are you driving at, Schnell?" "I'm trying to convince you that we are faced with a very clever criminal mind," I said. "A man with a fine talent. One who plans his crimes so well that they aren't even recognized as criminal." "Nonsense. You can't conceal any crime forever." "Forever isn't necessary, Chief. Just long enough to cover up completely, to remove all connection. We don't know how many bank tellers have been running on reduced salary because they somehow paid out a hundred in cashing a ten-dollar check. We couldn't demand an audit of all the big financial accounts in town, to know the why and wherefore of the transfer of any sum of money larger than the limit of petty larceny."