“We’ve never had a rubber duck,” Sarah said.

Sarah carefully pried the pages apart under running water. Most were ruined—smears of purple ink, drawings of cats and rainbows dissolved into abstract art. But one page near the middle had been protected by a waxy candy wrapper. The ink, though faded, was clear.

And so, armed with a flashlight and a reluctant sense of adventure, they stepped into the backyard. The air was thick with the smell of damp soil and jasmine. The exterior cleanout—a small, white plastic pipe stub with a square knob—stood near the foundation, half-hidden by overgrown mint. Mike twisted the cap off with a grunt.

“It’s not the trap,” her husband, Mike, said that evening, after dismantling the pipes under the sink and finding them pristine. “It’s further down. Probably outside.”