Murderer's chain

If Maudie had only given me the ten thousand dollars to invest in the Martian Development Company there would have been no reason to kill her. The money would have been more than tripled and my financial troubles would have been over. But Maudie has always been so unreasonable. Even though she grudgingly admitted that I had been right in the Martian venture, she still had no faith in my business judgment. She was as adamant as ever about parting with the smallest fraction of her vast fortune when I had the opportunity to step in on the ground floor of the Balsavius Six Mining Corporation.
Balsavius Six, in case you don't know, is the newest planet which Earth's space ships have touched. Everything about Balsavius has been kept strictly hush-hush. Only a handful of people have the slightest concept of the value of the new planet's mineral deposits. It just happened that one of the men in on the top secret was my friend Sylvester, and he was willing to cut me in on a slice of the corporation he was forming for as little as five thousand dollars on the line.
The problem was how to get my hands on that much folding stuff. The answer should have been easy. Maudie (Mrs. Maude Terrain) was one of Earth's wealthiest women and, after all, Maudie was my mother-in-law. The trouble with Maudie was that she was narrow-minded, prejudiced, I might say bigoted. She liked to boast that her family have come from good, solid Earth stock from the beginning of time and, while she mingled with the socially elite from Venus, she considered Martians crude, and refused to entertain guests from what she described as the minor planets.
Maudie's second trouble was that she was mean. Although her daughter, Isabelle, and I have been married for eight years, Maudie never did more than to provide us with a modest allowance. She always felt that I should work which, after all, is pretty non-sensical when there are so many ways for a man with a little capital to get rich quick.
Isabelle isn't like Maudie. She's easy-going, pliant, susceptible to flattery and, on Maudie's death, Isabelle would inherit her full fortune. So with a deal like this in the offing, it didn't take any great brain to see that Maudie's rapid demise would remove the single obstacle that stood between myself and untold wealth.