“Are they common, those machines?”

“Not anymore. They were first released in 1969.” She glances up at Cooper and her eyes have an unsettlingly predatory glint. “Find me his typewriter and I can use the TYPE classification system to nail him with this.”

Cooper makes a thin smile. “Talk to me about the paper.”

“I can see why Gerry’s sighing. I don’t think he’s going to get anything off it, even with the iodine. The cotton fibers in the onionskin are at least as old as the machine, and they’re just going to leach. There’s a little tear here, on the end of the fold—I think the attendant might have snagged it getting it out of the envelope. Now let me look at the signature.”

Brown completes photography on the letter from above and all angles, flips it with her forceps to photograph the reverse. Then she flips it back, switches off the bigger lamps, and darkens the room to use a handheld ultraviolet light, scanning minutely. Emma hears Bell’s soft breathing close by. She gets a sense of Brown’s office as some kind of outer space bubble, airless and quiet. When the ordinary office lights come back on, it’s a shock.

“It’s a blue ballpoint,” Brown says, “and it’s contemporary, but I won’t be able to narrow down the specific pen. I’ll need to use solvent to tell you which ink—are you okay for me to cut away a little section for the liquid chromatography?”

“This letter isn’t going to its receiver,” Cooper confirms.

“The handwriting is undisguised—he hasn’t used any embellishment, or written with his nondominant hand. He’s right-handed, by the way, but you already knew that. You don’t think that’s his name, Siegfried, do you?”

“He used Gutmunsson’s nom de plume in the salutation, so no. I think he’s using a moniker. I’m not sure what ‘Siegfried’ means.”

“Don’t you? Ed, you need to do more reading.” Brown takes the envelope out of the case with her steady forceps, deposits it into another clean case for continued examination, closes up the case with the letter to send back to Westfall for fuming. “Siegfried was the hero from Norse mythology. He slew the dragon Fafnir and married the Valkyrie Brynhild.”

“How do you know all this stuff?”

She grins. “Benefits of homeschooling.” Her grin fades. “The legend goes that Siegfried bathed in the dragon’s blood, and it made him invincible.”

Emma stares at the letter and feels a chill.

CHAPTER TWENTY-SIX

The front of the envelope is addressed to Gutmunsson, care of Evelyn Scott, St. Elizabeths Hospital, 1100 Alabama Avenue Southeast.”

Westfall has crowded them into his office, which looks like someone exploded an illegal ordnance inside it, and Bell is trying not to stare. How does the guy get any work done in here? The office is darkened and everyone looks at a section of the pale wall as Westfall displays stills from the video camera he used to record images of the front and back of the envelope.