“I'm so glad everybody is well. So what was the medical diagnosis in Anchorage?” Dirk asked.

Sandy and Sarah glanced at each other briefly with a searching look, then shrugged and shook their heads in unison.

“They didn't find anything,” Sarah finally said. “It's something of a mystery. We all showed signs of an inflamed respiratory track, but that was about it. Blood and urine samples came back clean. If we did inhale a toxin, it was purged from our systems by the time we reached Anchorage.”

“That's why we're here to pick up the sea lion. Hopefully, there will be some indicators still evident in the animal's tissue,” Sandy said.

“So, you're not here to see me?” Dirk intoned sadly with an exaggerated frown on his face.

“Sorry, Dirk,” Sarah laughed. “Why don't you come meet us at the lab later this afternoon after we do our analysis? We can go grab a late lunch.”

“I would like to know the results,” he agreed, then led the two on board to retrieve the frozen sea lion.

Once the mammal was hauled away, Dirk and Dahlgren helped secure the ship, transferring ashore the sensitive high-tech survey gear that was stored in an adjacent warehouse. With their docking shores complete, the crew of the Deep Endeavor gradually dispersed to enjoy a few days of R&R before the next project set sail.

Dahlgren approached Dirk with a rucksack tossed over one shoulder and the pair of crutches under one arm. Only a slight limp was noticeable from his calf wound when he walked.

“Dirk, I'm off to rustle up a date with a sexy teller I met at the bank before we shipped out. Should I see if she has a cute friend?”

“No, thanks. Think I'll get cleaned up and go see what Sarah and Sandy discovered from our sea lion Popsicle.”

“You always did have a thing for the brainy types,” Dahlgren chuckled.

“What's with the crutches? You've been off those things for three days now.”

“Never underestimate a woman's sense of sympathy,” Dahlgren grinned, placing one crutch under an arm and pretending to limp in agony.

“If I were you, I wouldn't underestimate a woman's ability to detect bad acting,” Dirk replied with a laugh. “Happy hunting.”

Dirk borrowed the keys to a turquoise NUMA Jeep Cherokee and drove a short distance to his rented town house overlooking Lake Washington. Although he called Washington, D.C." his home, he enjoyed the temporary assignment in the Northwest. The lush wooded surroundings, the cold, clear waters, and the youthful and vibrant residents who thrived in the sometimes bleak and damp weather made for a refreshing environment.

Dirk showered and threw on a pair of dark slacks and a thin pullover sweater, then downed a peanut butter sandwich and an Olympia beer while listening to a litany of messages on his answering machine. Satisfied that the earth had not come to a stop in his absence, he hopped into the Jeep and headed north on 1-5. Exiting east past the lush Jackson Park Golf Course, Dirk turned north and soon entered the park like grounds of Fircrest Campus. Fircrest was an old military complex that had been turned over to the state of Washington and now housed offices and operations for a variety of state government agencies. Dirk spotted a complex of square white buildings surrounded by mature trees and parked in an adjacent lot fronted by a large sign, stating: Washington state public health laboratories.

A perky receptionist phoned up to the small CDC office shared by the state lab and a few moments later Sarah and Sandy appeared in the lobby. A portion of the cheeriness they showed earlier in the day had clearly left their faces.

“Dirk, it's good of you to come. There's a quiet Italian restaurant down the street where we can talk. The Pasta Alfredo is great, too,” Sarah suggested.

“Sure thing. Ladies first,” Dirk replied as he held the front door open for the two scientists.

After the threesome shoehorned into a red vinyl booth at the nearby neighborhood restaurant, Sarah explained their findings.

“An examination of the sea lion revealed the classic signs of respiratory seizure as the cause of death. An initial blood test failed to reveal any concentrated levels of toxicity, however.”

“Similar to the test results for you three in Anchorage,” Dirk added between bites of bread.

“Exactly. Our vitals showed fine, though we still experienced weakness, headaches, and signs of respiratory irritation by the time we reached Anchorage,” Sandy added.

“So we went back and carefully reexamined the animal's blood and tissue and finally detected trace elements of the toxin,” Sarah continued. “Though not one hundred percent certain, we are fairly confident the sea lion was killed by hydrogen cyanide poisoning.”

“Cyanide?” Dirk asked with an arched eyebrow.

“Yes,” Sandy replied. “It makes sense. Cyanide is actually expelled rapidly from the human body. In the case of Sarah, Irv, and me, our bodies had naturally purged most, if not all, of the cyanide toxins before we stepped in the door of the Anchorage hospital. Hence, no trace remained when our blood samples were taken.”

“I've contacted the Alaska State Coroner's Office and informed them of our findings. They have not completed the autopsy report on the two Coast Guardsmen yet, but they will know what to look for. I am convinced that is what killed them,” Sarah said with a tinge of sadness.

“I always thought cyanide had to be ingested in order to be lethal,” Dirk remarked.

“That's what's commonly known, but it's not the only deadly form of the poison. Everyone knows of cyanide tablets carried by wartime spies, the deadly Jim Jones cyanide-laced Kool-Aid that killed hundreds in Jonestown, Guyana, and the Tylenol poisonings, which used cyanide. But cyanide gas has also been used as a killing agent. The French tried variations of cyanide gas against the Germans in the trenches during World War One. And though the Germans never used it on the battlefield, they did use a form of cyanide in the concentration camp gas chambers during the Second World War.”

“The infamous Zyklon B,” Dirk recalled.

“Yes, a beefed-up fumigant originally developed to kill rodents,” Sarah continued. “And, more recently, Saddam Hussein was suspected of using a form of cyanide gas in attacks on Kurdish villages in his own country, although it was never verified.”

“Since we packed in our own food and water supplies,” Sandy piped in, “the airborne poisoning makes sense. It would also explain the deaths of the sea lions.”

“Is it possible for the cyanide to have originated from a natural source?” Dirk inquired.

“Cyanide is found in a variety of plants and edibles, from lima beans to choke cherries But it's as an industrial solvent where it is most prevalent,” Sarah explained. “Tons of the stuff are manufactured each year for electroplating, gold and silver extraction, and fumigants. Most people probably come in contact with some form of cyanide every day. But to answer your question, it's unlikely to exist in a gaseous state from a natural source sufficient to reach any sort of lethality. Sandy, what did you find in the historical profile of cyanide deaths in the U.S.?”

“There's been a slew of them, but most are individual accidents or suspected homicides or suicides resulting from ingestion of solid cyanides.” Sandy reached down and picked up a manila folder she had brought along and skimmed through one of the pages inside.

“The only significant mass death was related to the Tylenol poisonings, which killed seven people, again by ingestion. I found only two references for multiple deaths from suspected cyanide gas. A family of four died in the Oregon town of Warrenton back in 1942, and in 1964 three men were killed in Butte, Montana. The Montana case was listed as a mining accident due to extraction solvents. The Oregon case was listed as undetermined. And I found next to nothing for prior incidences in and around Alaska.”