The Two Designs with One Signature

The Door into Summer

Dan's investigation of Eager Beaver and Drafting Dan turns an apparent coincidence into a personal mystery about memory, identity, and the closed loop of his own life.

increasing

Bearing strength in each event

decreasing

A Familiar Automaton A Familiar Automaton from "The Door into Summer". A Familiar Automaton The old design returns An Eager Beaver serves Dan in the recovery ward, and he recognizes in its structure the lineage of Flexible Frank.

A Familiar Automaton from "The Door into Summer". A Familiar Automaton The old design returns An Eager Beaver serves Dan in the recovery ward, and he recognizes in its structure the lineage of Flexible Frank.

A Familiar Automaton The old design returns An Eager Beaver serves Dan in the recovery ward, and he recognizes in its structure the lineage of Flexible Frank. Its refined design confirms that his early invention helped shape the machinery of the future. A patent number recorded Dan copies the earliest patent number, initially treating the discovery as professional curiosity. He assumes that the future's engineers may have developed the design from his work, though he does not yet know how it was recorded.

Drafting Dan's Signature Drafting Dan's Signature from "The Door into Summer". Drafting Dan's Signature A second recognition Dan tests Drafting Dan and finds that its controls and mechanical choices match the design he had once imagined.

Drafting Dan's Signature from "The Door into Summer". Drafting Dan's Signature A second recognition Dan tests Drafting Dan and finds that its controls and mechanical choices match the design he had once imagined.

Drafting Dan's Signature A second recognition Dan tests Drafting Dan and finds that its controls and mechanical choices match the design he had once imagined. Unlike Eager Beaver, this machine had never existed outside his earlier thoughts. A troubling question The first patent is dated 1970, which predates his return to that year. Dan wonders whether his memory is incomplete, or whether some unknown inventor has independently made the same choices.

The Names on the Patents The Names on the Patents from "The Door into Summer". The Names on the Patents A repeated inventor The archive records show D. B. Davis as inventor of both Eager Beaver and Drafting Dan.

The Names on the Patents from "The Door into Summer". The Names on the Patents A repeated inventor The archive records show D. B. Davis as inventor of both Eager Beaver and Drafting Dan.

The Names on the Patents A repeated inventor The archive records show D. B. Davis as inventor of both Eager Beaver and Drafting Dan. Dan accepts authorship of the first but fears that the second exposes a gap in his memory. An identity problem Two designs, filed under the same initials, make a coincidence seem nearly impossible. Dan considers amnesia as well as the possibility that both inventions belong to his own history in a way he cannot yet explain.

A Statistical Alternative A Statistical Alternative from "The Door into Summer". A Statistical Alternative Chuck's objection Chuck Freudenberg points out that many people share initials and that coincidences, however unlikely, still occur.

A Statistical Alternative from "The Door into Summer". A Statistical Alternative Chuck's objection Chuck Freudenberg points out that many people share initials and that coincidences, however unlikely, still occur.

A Statistical Alternative Chuck's objection Chuck Freudenberg points out that many people share initials and that coincidences, however unlikely, still occur. He asks Dan to verify the inventor's full identity before spending money on psychological investigation. A better explanation emerges The possibility that another D. B. Davis designed the machine does not fully reassure Dan, but it breaks the apparent certainty of amnesia. Chuck's friendship keeps a puzzle from becoming a conviction that Dan has lost his mind.

The Loop Revealed The Loop Revealed from "The Door into Summer". The Loop Revealed The same inventor acts twice Dan builds Drafting Dan after returning to 1970, then sleeps into the era in which the patent already exists.

The Loop Revealed from "The Door into Summer". The Loop Revealed The same inventor acts twice Dan builds Drafting Dan after returning to 1970, then sleeps into the era in which the patent already exists.

The Loop Revealed The same inventor acts twice Dan builds Drafting Dan after returning to 1970, then sleeps into the era in which the patent already exists. The design's early patent is therefore not evidence of a stranger or a missing memory; it is a record of his own earlier-in-time work. A closed causal chain Dan recognizes that his actions fit one self-consistent history. The machine's authorship becomes a consequence of time displacement rather than a mystery that demands a second inventor.

December 2000, at Sawtelle

Early 2001, at Aladdin's salesroom

Spring 2001, after the patent search

One Friday night in spring 2001

After Dan's return to 1970 and second awakening