The following morning, she strolled into the nearby town for supplies. A dusty little bookstore caught her eye, small, unassuming, nestled between a bakery and a crystal shop. Something about the cracked paint on the door made her pause. It was the sort of place her mother would have called an interstitial space, where the veil between worlds was thin.

 

As she stepped inside, the bell chimed.

 

A woman in her sixties peered up from behind the counter. "You looking for something in particular, hon?"

 

Elena held back for a moment. "Is there anything you can tell me about... time travel? Or possibly about…doppelgängers?"

 

The woman's stare became sharper, as though she had already been asked that question. She rose slowly and slipped behind a beaded curtain.

 

When she came back, she presented to Elena a small, ancient book bound in blue cloth:

"Temporal Echoes and the Paradox of the Self"

 

"There is no barcode," murmured Elena.

 

"How do I pay for it?"

 

"Payment is not required," the woman said. "It discovers whoever it needs to."

 

She left with the book and two odd side glances from people who passed by one from a kid who turned to stare and then turned back, and another from a guy who almost dropped his book and said, "You're really here!"

 

Elena read the whole book that night. It was part science, part metaphysics, and disturbingly specific.

 

One passage completely halted her:

When an echo temporally occurs, the self may manifest as both warning and witness. The closer the echo approaches the origin point, the more perilous the loop becomes. If unresolved, the result is entrapment, where the self lives out the same 48-hour cycle with ever-increased degeneration.

 

A loop.

 

Entrapment.