"A ring?" Susan looked doubtful. "Tankado'smissing a ring?"

"Yes. We're lucky David caught it. It was a realheads-up play."

"But you're after a pass-key, not jewelry."

"I know," Strathmore said, "but I think theymight be one and the same."

Susan looked lost.

"It's a long story."

She motioned to the tracer on her screen. "I'm notgoing anywhere."

Strathmore sighed heavily and began pacing. "Apparently,there were witnesses to Tankado's death. According to theofficer at the morgue, a Canadian tourist called the Guardia thismorning in a panic—he said a Japanese man was having a heartattack in the park. When the officer arrived, he found Tankado deadand the Canadian there with him, so he radioed the paramedics.While the paramedics took Tankado's body to the morgue, theofficer tried to get the Canadian to tell him what happened. Allthe old guy did was babble about some ring Tankado had given awayright before he died."

Susan eyed him skeptically. "Tankado gave away aring?"

"Yeah. Apparently he forced it in this old guy'sface—like he was begging him to take it. Sounds like the oldguy got a close look at it." Strathmore stopped pacing andturned. "He said the ring was engraved—with some sort oflettering."

"Lettering?"

"Yes, and according to him, it wasn't English."Strathmore raised his eyebrows expectantly.

"Japanese?"

Strathmore shook his head. "My first thought too. But getthis—the Canadian complained that the letters didn'tspell anything. Japanese characters could never be confused withour Roman lettering. He said the engraving looked like a cat hadgotten loose on a typewriter."

Susan laughed. "Commander, you don't reallythink—"

Strathmore cut her off. "Susan, it's crystal clear.Tankado engraved the Digital Fortress pass-key on his ring. Gold isdurable. Whether he's sleeping, showering, eating—thepass-key would always be with him, ready at a moment's noticefor instant publication."

Susan looked dubious. "On his finger? In the open likethat?"

"Why not? Spain isn't exactly the encryption capitalof the world. Nobody would have any idea what the letters meant.Besides, if the key is a standard sixty-four-bit—even in broaddaylight, nobody could possibly read and memorize all sixty-fourcharacters."

Susan looked perplexed. "And Tankado gave this ring to atotal stranger moments before he died? Why?"

Strathmore's gaze narrowed. "Why do youthink?"

It took Susan only a moment before it clicked. Her eyeswidened.

Strathmore nodded. "Tankado was trying to get rid of it. Hethought we'd killed him. He felt himself dying and logicallyassumed we were responsible. The timing was too coincidental. Hefigured we'd gotten to him, poison or something, a slow-actingcardiac arrestor. He knew the only way we'd dare kill him isif we'd found North Dakota."

Susan felt a chill. "Of course," she whispered."Tankado thought that we neutralized his insurance policy sowe could remove him too."

It was all coming clear to Susan. The timing of the heart attackwas so fortunate for the NSA that Tankado had assumed the NSA wasresponsible. His final instinct was revenge. Ensei gave away hisring as a last-ditch effort to publish the pass-key. Now,incredibly, some unsuspecting Canadian tourist held the key to themost powerful encryption algorithm in history.

Susan sucked in a deep breath and asked the inevitable question."So where is the Canadian now?"

Strathmore frowned. "That's the problem."

"The officer doesn't know where he is?"

"No. The Canadian's story was so absurd that theofficer figured he was either in shock or senile. So he put the oldguy on the back of his motorcycle to take him back to his hotel.But the Canadian didn't know enough to hang on; he fell offbefore they'd gone three feet—cracked his head and brokehis wrist."

"What!" Susan choked.

"The officer wanted to take him to a hospital, but theCanadian was furious—said he'd walk back to Canada beforehe'd get on the motorcycle again. So all the officer could dowas walk him to a small public clinic near the park. He left himthere to get checked out."

Susan frowned. "I assume there's no need to ask whereDavid is headed."