The machine hummed at four percent charge when Dana knocked on the garage door for the third time that night.

"You're going to blow the breaker again," she said.

Warren didn't look up from the capacitor bank. "Forty more minutes."

"It's midnight."

"Forty minutes." He tightened a bolt that didn't need tightening. "Then I'll know if it works."

She sat on the workbench stool she'd sat on for eleven years of his projects, none of which had ever hummed like this one. The garage smelled like ozone and burnt coffee. On the whiteboard behind him, a single date was circled in red: March 14, 2041.

"That's fifteen years from now," she said.

"I know."

"You always go backward. Every prototype. You said the math only worked backward."

"I fixed the math." He finally turned around, and his face had the specific exhaustion of a man who hadn't slept in a way that counted for four days. "I'm not going back to fix anything, Dana. I'm going forward. I want to see if we're still here."

She didn't answer that. The dog, an aging shepherd mix named Biscuit, lifted his head from the concrete and settled again.

"The doctor said six months," Warren said, quieter now. "I want proof there's a Tuesday in 2041 where you're still yelling at me about the breaker."

The machine reached ninety percent. It didn't look like science fiction. It looked like a shower stall wired to a generator, with a keypad bolted to the frame where a soap dish should have been. He'd built the frame from a stall he'd pulled out of the house during a bathroom renovation two years back, before either of them had heard the word carcinoma in a doctor's office.

At ninety-eight percent, Dana stood up. "Take me with you."

"It's one-person. I told you the field collapses past a certain mass."

"Then don't go at all."

He looked at her for a long moment, and something in his face softened into the version of him she'd married, not the version that had spent two years disappearing into a garage full of capacitors. "If I don't go," he said, "I'll spend the rest of whatever time we have wondering. I'd rather know."

The machine chimed. One hundred percent.

He stepped inside the stall. The door, an actual shower door with a chipped decal of a seashell still stuck to the glass, hissed shut on its new magnetic seal. Dana pressed her palm to it. Through the frosted glass she watched him type the date, watched the numbers glow, watched him mouth something she couldn't hear over the rising whine of the coils.

The light that followed wasn't blinding. It was more like a held breath, a half second where the whole garage seemed to lean sideways. Biscuit barked once, sharp, and then it was over.

The stall was empty.

Dana didn't call the police. She didn't call anyone. She sat on the workbench stool until the sun came up, and then she sat there through the next day, and the next, feeding Biscuit, checking the readout on the machine that still glowed a soft standby amber, waiting for a version of her husband who was fifteen years and one biopsy away to walk back out of an old shower door.

He never did.

What she found, six days later, going through his files to cancel his email accounts, was a folder labeled simply 2041. Inside was a single photograph, timestamped, dated correctly, taken from inside a garage that was unmistakably this one. In it, an old shepherd mix she didn't recognize slept by a workbench. A whiteboard on the wall had a date circled in red, but it wasn't March 14, 2041.

It was tomorrow.