RIYADH, SAUDI ARABIA—Touting the state-of-the-art electric execution device’s energy efficiency, sleek design, and whisper-quiet machinery, billionaire Elon Musk gave Saudi investors a presentation on a new autonomous adulterer-beheading machine he has invented, sources confirmed Tuesday. “I’ve been thinking a lot lately about the best way to revolutionize and reimagine the way we approach making adulterers pay the ultimate price for their sinful indiscretions,” said Musk, who paused to invite his prospective investors to consider what a hassle old-fashioned executions can be before he unveiled his prototype for a solar-powered, self-activating guillotine capable of seamlessly beheading adulterers with 10 times the speed of an ordinary blade. “On just a single charge, this compact machine can efficiently decapitate more than 5,000 women accused of adultery—all while eliminating the need for a human executioner, who would only be required to make small corrections in the rare event the device mistakes a torso for a neck.” When informed through his interpreter that adulterers in Saudi Arabia are traditionally stoned to death, Musk reportedly did not pause in his presentation, asking for a volunteer to feed a head of lettuce into the machine so he could demonstrate its clean, mess-free cuts.