Marble derby was the Saturday brainstorm. The kids yanked the tape measure to its full extension and snapped it back, over and over, until one of them had the idea to roll a marble in its 25-foot gutter. The bubbly effects of inspiration lingered until Sunday morning when they both launched a collective enterprise: their invention business, headquartered in the laundry room. A domestic testing facility was established, and prototype experiments were conducted throughout the day. I am instructed to knock on a door. I do so. The door swings into a room in the center of which sits my son, pulling the string tied to the doorknob. He then points a National Geographic walkie-talkie at me and says, "What the," then presses a button that makes a loud bleep sound, "do you want?" Giggling is the surest measure of the success of an invention. Later, in the laundry room, sitting on top of the machines, one of them drops a pen into a dusty canyon, which prompts the other to invent the means to retrieve the pen. The device involves string and a wire hanger. The day's work can be reviewed in the torn sheets of notebook paper curled into a plastic mug beside another plastic mug of multicolored pens, both precariously balanced on the washing machine. I am not allowed to inquire into the details of these inventions, as they are still under development and likely to lead to several patents. I consider issuing multiple marbles down opposite ends of a tape-measure chute and observing the collisions. The joy of experiment lies not in the discovery of useful things but in the misuse of boring things. The kids call for me again, and I walk up the stairs to the second-floor laboratory. Surprise is the only desired outcome, and giggling cannot be patented.