Chowder took his time noticing. He was a foolish dog, though German shepherds are famously bright. Perhaps the white ones like Chowder, rabbity and smiling, had been bleached of their smarts. Beth, who Molly was dating, had owned Chowder for ten years. Ten frustrating years, probably, though Molly had only met Beth last February. She pictured the rodenty puppy he must’ve been, the birthday cakes he’d flattened, the urine sprinkled on carpets like holy water.

When Chowder saw the squirrel, he didn’t stop to point or stare, judge distance or probability of success. He tore off across the frosty grass and rinds of stale snow and slipped down the bank onto the river. He turned wild for a second, properly vicious. His hackles rose, his tail flagged, his teeth golden against his white coat. Even when his paws slipped, they slipped together, all four at once, propelling him farther and faster across the ice.

Just as Chowder was an inch from seizing the squirrel, thunder sounded and the ice gave way. The squirrel vanished into the rip without disturbing the river, and Chowder followed, faithful to the chase, pitching nose first into the mouth of charcoal water.

For a heartbeat, his tail stuck out, whiter than the ice or the overcast sky. Molly wondered if anyone was watching from the Weeks Footbridge or the Lowell Towers or that mysterious factory across the river. But then Chowder was gone and the squirrel was gone and Molly was still standing on the bank. She hadn’t taken a step.

There was a hole in the river now. A gray-blue shadow that couldn’t be big enough to swallow a chihuahua, much less a shepherd and a squirrel. Molly watched the hole for longer than any mammal’s lung capacity before she realized she should move, take action.

She hurried to the water’s edge and slammed her foot on the ice. Her sneaker swam around like crazy—ice was slippery, of course. She couldn’t cross it. She wished she had skates. Could she rent skates quickly, or steal some off a kid? She paced the bank, scanning for a sturdier path of ice to the hole. She called Chowder’s name until her voice gave out, straining for an answering splash.

Leaving felt wrong, but what else could she do? Walking back through Harvard Square, shaky with uncertainty that what had happened was real, her steps unsteady on the flagstones, the leash grew heavy around her neck. She was balling it up to stick in her bag when a kid in a VERITAS = BEER sweatshirt said, “All you need is a dog!”

A shot of acid struck Molly’s throat. “Are you volunteering?” She restrained herself from slapping his fat prodigy cheeks.

She returned to Hurlbut Hall, commonly known as Pukeass, to the first-floor suite where Beth was a tutor. Beth was away for last night and all of today, presenting a paper in Delaware, and had asked Molly to stay with Chowder. Harvard tutors were allowed to have pets on the first floor. Beth said that was because the dogs exited quickly without sloughing dandruff on the stairs and halls. Some of the students on the upper floors had sensitivities.