As Sam sat drinking his tea, his mug cracked.
The crack wasn’t noticeable. It was one of those hairline cracks, and in dark pottery with a black glaze, was essentially invisible. The crack ran from the edge opposite the handle down to the bottom of the mug.
As Sam took another sip, the crack slowly filled. He set his mug down and rustled the newspaper, and the moisture seeped into the clay of the mug. It moved like roots, extending further and further into the baked clay, a nanometer at a time.
Sam reached his hand down, lifting the mug and taking another sip. The strain of gravity pulling the liquid toward it caused the crack to open infinitesimally wider, the tendrils spreading faster and deeper. He set the mug down again and read another article.
The liquid kept spreading like a virus through an uninocculated population.
Sam lifted his mug again for a sip. Just as it neared his lips, the crack reached through the clay. Water sloshed past his lips, while a single drop beaded at the base, then fell. With that, the pottery gave up and let go, breaking apart in his hand and splashing hot liquid all over his new pajamas.
After cursing savagely, Sam walked to the bathroom and threw his pajamas in the laundry, leaving clay and coffee on the kitchen floor.