47

Heathrow Airport, London

The seismic shift of going from air to ground lurched Salem awake. She sat up, the movement triggering a searing headache. She blinked back the pain, her eyes watering.

“Here’s some water.”

She pushed away the pressure at her mouth, swiping at her face. “Charlie?”

“Yeah.”

His blurry image came into focus. They were on Alafair’s plane. Alafair was sitting across from Salem, her face sharp. Charlie was kneeling in front of Salem. He appeared peaked, but better.

“I thought you were dead,” Salem said.

Charlie smiled his crooked grin. “I felt dead. And you were on your way to joining me. I don’t know what was in those remedies Alafair gave us, but it brought us back from the brink.”

Salem was wearing different clothes. Her windpipe squeezed. “My parka.”

Alafair tossed her chin toward the pull-down table. “All your clothes are over there. I’ve not removed anything from your pockets.”

Salem glanced from Charlie to Alafair. “How long have I been out?”

“It took us three hours to receive clearance to fly out of Dublin. We were in the air a little shy of two hours.”

“I came to about an hour ago,” Charlie offered. “We’d both been put in new clothes.”

“You’d pissed yourself,” Alafair told Charlie. “Your fever had returned. I cleaned and dressed both your wounds and put you in new clothes. I also injected you both with antibiotics my pilot obtained while we were in Kildare.”

Salem stretched her leg in front of her. It was stiff but no longer felt hot. She rubbed her hand along the front of the soft pants Alafair had dressed her in. The wound was well-bandaged, tender but contained. She drew in several deep breaths, her headache receding. “Thank you.”

“She wouldn’t let me look at the clue,” Charlie complained, but it sounded good-natured. “Said we had to wait until you woke up.”

Salem shoved open the window covering. Except for the landing lights, it was dark outside. “Where are we? What time is it?”

“Heathrow, this side of six AM,” Alafair said. “A body was discovered at the Gloup in Kirkwall. The ID was for Bode Janus, an American. It’s only a matter of time until they connect you to him and then track our plane to Dublin. We needed to get out, and London was the closest. The question is, where to next?”

Salem waited until the plane came to a full stop before testing her leg. It was weak but held her. She walked to the table, rifled through her parka pockets, and tugged out the stoppered glass test tube. “Charlie,” she said, the time at Kildare coming back to her in fits and bursts. “I saw you get taken by a guy in a long coat. You were leaning against the church wall, and then you weren’t.”

He grew pale. “Yeah. I think it was the Order’s number-two assassin. A man who can supposedly change the shape of his face. I don’t know what he intended to do with me. But then the Grimalkin jumped him, same guy as from the Gloup. Slid a knife right into his throat. I fell back, did my best to blend into the crowd. That’s when Alafair found me and shooed me back to the car.”

Alafair’s eyes glittered like sharp ice. “I needed to get us away from the body on the ground.” She turned her attention to Salem. “And I found you shortly after.”

Salem nodded. Something was nagging at her. She needed to be alone with her thoughts to sort it out. She returned to her seat, removing the stopper and the scroll of paper. She palmed it flat against her tray table, noting that neither Alafair nor Charlie seemed surprised by its blankness. “I need the B&C. And—”

“Research on sympathetic ink?” Alafair asked.

Salem frowned.

Alafair shrugged. “You’re not the only one who knows her way around codes. It’s a blank sheet of paper, isn’t it? Must be an invisible ink, and not an organic fluid, like lemon juice or artichoke dye. Wouldn’t stand the test of time. That leaves sympathetic inks, which would make more sense anyways given Franklin’s scientific background.”

“Your pilot picked up iodine with the first-aid supplies?”

“I think so.” Alafair reached for a bag and dug around, producing a plastic bottle of brown-purple skin disinfectant. Her expression said she was curious but was going to watch and learn rather than interrupt with questions.

Not so Charlie. “Don’t you have to know what sort of ink was used to decide what will reveal it?”

Salem shook her head. “In World War I, both the Germans and the Americans used invisible ink. Because most organic inks could be revealed by exposing them to heat, they weren’t considered reliable. Sympathetic inks made from copper sulfate, iron sulfate, and cobalt salts were harder to decrypt. The Allies discovered that exposing paper to iodine vapor will turn any of the paper’s altered fibers brown. So, anything that was wet will change color.”

Alafair strode to a cupboard. “You’ll need to heat the iodine.” She dug around and came up with a one-cup electric tea pot. “This should do the trick.”

Salem plugged the pot in before filling it with iodine. “Cover your nose and mouth,” she said. “You’re not going to want to breathe this in.”

Her eyes started watering immediately. When the purply surface rippled, the hot, inky smell scalded her mucous membranes even through her sleeve. “You two don’t have to stay so close.”

“You couldn’t pay me to leave,” Charlie said, the collar of his t-shirt hooked over his nose and ears.

Alafair didn’t even bother to respond.

A bubble burped through the surface, followed by another. Soon, the iodine was at a rolling boil, its violet vapors floating up, turning the teapot into a witch’s cauldron. Salem held the unrolled scroll above, close enough to feel the heat on her knuckles. The paper sucked up the vapor. She allowed some doubt to seep in. This might not work. The scroll may be truly blank. Or, if someone had discovered it before Salem and already heated the ink, the clue would not be recoverable.

A new thought struck her: some inks revealed their code only briefly, and then it was gone forever.

“Charlie, take out your phone. I need you to snap a photo of anything that appears.”

He dug in his pocket with his good hand.

A kiss of color appeared on the corner of the paper.

The softest moan of pleasure escaped Alafair.

The spot of brown expanded as if a ghost was writing in front of them. The shapes appeared slowly, then faster, a furious staccato of brown flowing from the left to the right as the iodine vapor breathed life into the paper.

And then it was done.

The clue revealed.

“Another code,” Charlie said, snapping a photo, his disappointment heavy in his voice.

Alafair’s stare drew Salem’s like a magnet. They both understood. It wasn’t a code, it was the original code: written language, breakable only by those who knew the alphabet.

Or in this case, the aleph-bet.

“It’s Hebrew,” Alafair said. “Rosalind Franklin’s second language.”

Salem unplugged the pot of iodine and put the lid over the top to make room for the B&C Alafair was handing her. “Send me that photo,” she ordered Charlie.

It arrived in her email simultaneous to her getting online.

Gaea scooped up the image Charlie sent and immediately translated it into English.

No justice without mercy.

Salem swallowed past the poisonous tang in her throat.

Justice. Mercy.

She knew exactly where Rosalind Franklin wanted them to go.