***

Evelyn and I are standing now on opposite sides of the hot spring, the east and west sides of the U-shaped north end. The Bazooka is bobbing and weaving out in the middle as though trying to break free of its tether line and escape the upsurge of water and gas from the vent below. On my side of the hot spring, the line is lashed to a small desiccated pine log Evelyn and her students used as a kind of tie-down. On Evelyn’s side, it is looped around a white-and-black speckled granitic boulder. Beside me, a two-gallon, aluminum foil-lined Igloo cooler awaits open and ready.

The trick here will be to gather the Bazooka in so that it remains submerged in the heated water at all times; too much exposure to open air could foul some of the colonized glass wool. Then we’ll have to get the thing out of the water and into the Igloo as quickly as possible without allowing it to touch anything: the sides of the hot spring, the hard packed ground, our clothes, and certainly no buffalo feces. It’s essential that as little stray non-hyperthermophilic DNA as possible come into contact with the glass tube or glass wool.

Evelyn is taking a series of pH and conductivity readings with a little handheld meter on her side of the hot spring. I’m not sure why, but it is essential that before we bag the experiment she records the exact state of the water in terms of pH and ionic charge, which is constantly changing according to conditions at the heat source some thousands of meters below the hot spring.

As I watch Evelyn work, I try to figure out just how I’m going to handle my end of the tether line. I’ll take my cues from Evelyn, but at the same time I’m not interested in messing this up. Even before we left San Francisco, Evelyn was telling me that this experiment is something new for her and will allow for a look at the full range of microbes that inhabit this particular hot spring, especially those rare and sometimes fragile ones that come spewing out from the vent and the natural conduits and piping far below. If everything goes well and we get the Bazooka safely sealed inside the sterilized cooler and then inside another cooler full of dry ice, the entire trip will be a success. If things go badly, if Evelyn or I screw anything up now, this trip could go from bad to worse.

There is, of course, a great deal at stake here for Evelyn and her collaborators, who are in stiff competition with others around the globe. Everyone wants to solve the mystery of these strange hot-water bugs, and everyone wants to solve the big looming question of whether these bugs are the earliest to have come about on Earth and, very possibly, other once-watery planets or moons in the solar system: Mars, Jupiter’s Europa, Saturn’s Enceladus, among others.

If Evelyn and her colleagues come to understand, by way of the Bazooka and other experiments, how these living analogues for those most ancient of creatures live, die, and then become fossilized in the rock record, which they’ve been doing in Yellowstone hot springs for millions of years, we will be that much closer to answering those prickly questions about how life got started and how we go about identifying microbial fossils in rock formations on Earth and elsewhere.

My hope is that things do pan out that way, and that it happens in Evelyn’s lifetime. She’s put too much into it for anything less.

“Okay,” Evelyn calls out now from the other side of the hot spring. She’s finished with the pH/conductivity meter and kneeling beside the granite boulder that has the tether line wrapped around it. “We’ll both cut the line, then I’ll walk my end over to you. The float and tube assembly will start to drift over that way”––she points to her right, toward the north-most edge of the hot spring––”but not that much. If it gets too close to the edge, though, I’ll walk back over here and we’ll keep the line a little taut and the tube assembly in the water. Then we’ll try again. It’s all timing on this one.”

“Okay,” I say and nod. I’m on my knees, too, beside the pine log, poised and ready to cut my end of the line free with a utility knife. “Should I do it?”

“Go ahead.”

I grip the tether line with my right hand, and with my left cut through the rope with one clean stroke of the blade. Then I set the knife down beside the hot spring edge and stand. Some of the rope on my end, only three or four feet of it, lifts out of the near-boiling water. In the now icy, ever-present wind, long smoky strands of water and steam blow from the rope and streak sideways through the air.

I look over at Evelyn and see that she is having some trouble cutting through the rope. Instead of a knife, she has orange-handled scissors, which, if I’d seen that was what she was going to use, I’d have suggested something else. She’s still kneeling beside the boulder but hunched now, making a kind of sawing motion while she tries to cut with the scissors.

“Getting it?” I call out to her.

“This sucks!” she says, straining, still sawing. She looks over at me and laughs an embarrassed-frustrated laugh. “The line’s hardened or something.”

“You should come over and get the knife? It’ll cut right through.”

“I think I might have it,” she says, and she does. The line is cut, but somehow she’s managed to let go of it with her other hand, and the end of the rope slides like a narrow white eel into the hot spring. She reaches into the near-boiling water to try to get hold of it but then pulls her hand back quickly. “Shit,” she says, grimacing and shaking the pain away.

“Are you all right?” I call out, the Bazooka and unattended line beginning to drift away from the upwelling of heated water.

“Fine,” she says and jogs to the north hot spring edge where it seems the Bazooka is heading. “Goddammit, I can’t believe this.” She goes to her knees and readies herself.

“Can you get the rope?”

“I think so,” she says, the wind gusting now, pushing the Bazooka like a little red boat gone adrift. “The line floats, so I should be able to get it.”

The Bazooka moves to within three feet from the edge, and Evelyn reaches out over the hot spring with one hand. I imagine for one quick, horrifying second the crusty sinter rock giving way under her feet, and Evelyn sliding to her death into the boiling hot spring.