A/N: The story is now in chronological order.
Prologue: The Past
The Rats of (D)ARPA
It's 1971 when ARPA calls Bell and Bishop out of the lab to investigate a body (if you can call it that: it's a ball of goo with hard parts inside). They dissect the corpse down to slivers of its odd bones, and though they don't inform the overlords, they privately agree that the thing (whatever it is) is not of this world.
1972 brings more bodies, all of them exactly as human as the first one (which is to say, not really), but they're starting to have identifiable legs and arms. There are other discrepancies, too, between the body from '71 and the several that show up by June of this year, and they have to admit that either the organism is evolving, or its build is being upgraded. Walter argues the latter, seeing as how the 'organism' bleeds liquid mercury.
In the fall, an event takes place at a power line junction in Utah. A pylon disappears (along with the power to 4 counties) and is replaced by a ring of upright metal rods, in the center of which lie another body. William Bell takes twenty-four minutes on site to solidify a theory of interdimensional visitation. Walter takes twenty-three to reach the same conclusions, but is distracted by a call from his wife and Belly takes all the credit for saying it first.
Government agents buzz about Klaatu and Pod People as they load the rods into a truck bound for the lab. Bell and Bishop let them steep in the alien ideology without mentioning their theories, because DARPA (not plain old ARPA anymore, having added the D "for the shit of it," according to Walter) won't be able to steer or smother the research they don't see coming.
1973 is a pressure cooker. Between Vietnam and oil fiascos, DARPA breathes down their necks about the mercury men problem: a problem, in that they keep appearing, and in that sooner or later some suburbanite is going to find one in their backyard. The War in Southeast Asia is a big enough PR issue without having to spin an ongoing alien invasion into something kinder and gentler.
But by April, Bell is the only one making progress. Walter is bogged down by DoD special requests, last-ditch efforts to save face in Vietnam: nerve regeneration, memory erasers, post-death interrogation; but Bell is a clever diplomat and plays up the alien paranoia to the right bureaucrats, keeping himself assigned to what he calls (privately, between Walter and himself) the Pattern. His approach consists mostly of reverse engineering, which is rough when he's never seen most of the component tech before.
The '72 rods taunt Bell until 1975 rolls around. Walter, finally cut loose from the DoD, returns to the lab from his latest appointment in Arlington and finds his friend sitting at a table, watching a ferrofluid wind its pointy way up one of the mystery rods.
"Walter," Bells says, "I've cracked it."
With the electromagnetic field of the interdimensional beacons spelled out for them, 1976 is fruitful. On New Year's Eve, the two men drink a cooler of Narragansetts and stare through a freshly minted window into another world.
"Go home," Bell says, twenty minutes to midnight. "Tell Elizabeth you're not going to be Gerald Ford's dog. We don't need anyone else anymore."
And Walter does go home. He does tell his wife exactly that, and Elizabeth starts feeling secure enough to consider starting that family they've been talking about.
1977 is a year of waiting. Bell works tirelessly to perfect his window. He's building something else, too: a window he'll be able to walk through.
Walter contracts himself out (at a premium, this time) to DARPA, but only to get his hands on the newest wave of mercury men. They look like people, and not just generic people, but specific people. Walter waits to see how they'll evolve. But mostly, Walter waits for his son to arrive.
In 1978, Walter sits in the hospital waiting room and chain-smokes his way through Peter's zeroeth birthday. After he sees Peter's red, squashed face for the first time and subsequently gets shooed from the room, he goes looking for Bell with two blue-wrapped cigars in hand. But William Bell is gone.
Instead of Bell, Walter finds the Gateway, glowing and alive. There are notes taped everywhere, in duplicate and triplicate: on the Gateway itself, on the numerous power cables, and on the three backup generators being vented through the basement windows. Every single one was some variation on a warning not to turn anything off.
There's a longer note on Walter's desk, though not much longer. "If I don't make it back," it reads optimistically, "you couldn't have saved me by being here."
When Bell comes back, he collapses just over the threshold of the Gateway. Walter drags him into the Electro-Magnetic Field Regulator and it's days before he's back up and at 'em.
"You wouldn't believe what they've got Over There," Bell says when he can speak again. He's brought back notebooks filled with diagrams and a suitcase packed with small electronics. Walter digs through them and doesn't recognize most of the brand names. Some of them, he can't recognize what they're for.
"You should go," Bell says. But Walter won't go through that Gateway. He has a son, now. He can't take risks.
"Our future is made of risks," Bell tells him.
"Yours, maybe," Walter says.
"No - everyone's. If you want your son to grow up, you're going to want to start taking all the risks you can." It's cryptic and it's meant to be. Bell is gone again the next day, and Walter notices that a few pieces of lab equipment are gone with him. They don't come back when he does.
"They were the cost of my souvenirs," Bell explains, later. "A payment to balance the universe. An even exchange."
Bell appears at the Gateway like a swarm of hornets a day after he leaves on his third trip. "They're clones," he says, as he stumbles into the EMFR and latches the door behind him. As the magnets spin up, he mouths through the glass: "And I think we're at war."
Once he's out, he spreads a sheaf of stolen mimeographs out like pieces of a map on Walter's desk.
"How did you get these?" Walter asks. They must be important, but he doesn't know how.
"I drugged farmer Fitzgibbon's cat," Bell says, making Walter smile.
"I suppose, though," Walter says as he peers over the papers, "that we're more like the rats of DARPA."
"In that we became intelligent, and escaped?"
One of the purplish images shows a man with smoke coming out of his eyes. Despite the gratuitous use of deist symbolism, Walter finds it arresting. There's writing behind the face - only four letters, repeated, which means there's only one thing it could be - but the think tanks at Cambridge and Harvard have only just managed to sequence DNA, and Walter can't believe that the Other Side is capably of simply jotting down the recipe for a man.
"This," he says, lifting the sheet from the rest. "What is it?"
"Their future," Bell says, studying over Walter's shoulder. "Or so they believe."