Lethal Legend by Kathy Lynn Emerson

Dunbar’s. Diana hadn’t thought Mrs. Monroe knew the archaeologists except in passing. They’d been camping out, doing their own cooking, until ... until they’d been poisoned.
    Diana frowned. Was it possible? Could this, somehow, be connected to the earlier attempt on the lives of Ennis, Carstairs, and Amity?
    When Somener’s two watchmen had pulled the tender up on shore, Diana picked her way towards it, careful to avoid sharp rocks, clumps of wet seaweed, and barnacles. Miss Dunbar pushed ahead of her. By the time Diana caught up, the other woman stood beside the boat, staring without visible emotion into the lifeless face of Frank Ennis.
    “He’s dead,” Ben said. “Murdered.”
    The bald announcement did not surprise Diana. It only confirmed her worst fear. On almost everyone else, however, it had the effect of a firecracker in a church.
    Miss Dunbar took a quick step back, hands raised as if to ward off a blow. Mrs. Monroe gasped. MacDougall went stiff as a poker, except for the quivering of his mustache. Landrigan started, then looked wildly about, as if he expected an ax-wielding madman to leap out from behind the nearest boulder.
    Only the men in the tender failed to react. Diana presumed that was because they’d already heard Ben’s opinion on the cause of death.
    Miss Dunbar recovered first. “What are you talking about?” Irritation brought bright spots of color into her cheeks. “He can’t have been murdered. It was an accident. A tragic accident.” Her voice broke on the last word.
    It was not that Miss Dunbar did not have softer emotions, Diana decided. She was simply adept at hiding them.
    “See for yourself.” Ben indicated a section of the hose attached to Ennis’s helmet.
    Diana’s eyes widened when she observed its condition. The once-smooth surface was now horribly corroded, pitted and broken to the point where water had been able to get in.
    “I admit I’m no expert,” Ben said, “but I don’t need to be to see that this hose has been treated with a chemical—an acid of some sort that reacted to the salt water—causing it to eat into the hose. My best guess is that all seemed well until after Ennis reached bottom. Then the hose failed too quickly for him to do anything to save himself.”
    “Horrible,” Mrs. Monroe whispered, turning away. Diana hadn’t even realized she’d followed them down to the tender.
    It was horrible, she thought. It was also part and parcel of the strange happenings on Keep Island. Graham Somener’s request to his old friend had placed Ben smack in the middle of Somener’s troubles.
    “Did he say anything?” Diana asked Paul Carstairs. “Shout for help? Indicate he needed to be hauled up?”
    “Nothing,” Carstairs said.
    George Amity confirmed it. “Not a peep.”
    “It was only when I asked Frank a question through the speaking tube and didn’t get an answer that I realized something was wrong. From our end, the pump looked to be going great guns. The air must have been venting straight into the bay.” The hand Carstairs scraped over his pale face trembled.
    “Shouldn’t there have been bubbles?” Diana asked. “If the hose failed, shouldn’t you have seen bubbles rising to the surface?”
    “Didn’t notice,” Amity admitted.
    “Wouldn’t matter,” Carstairs said quickly. “As long as Frank’s diving weights were still in place, we wouldn’t have been able to haul him out quickly enough to save him.”  
    Miss Dunbar had been examining the diving suit and helmet they’d taken off the body. “There was nothing wrong with this equipment earlier today. Frank inspected it himself. He was always careful.”
    “If it was acid applied to the hose,” Ben said, “it might not have been visible.”
    He’d retrieved his coat and shoes but did not put them back on. He was dripping wet and shivering, as was Graham Somener. Miss Dunbar didn’t seem to notice.
    “Wouldn’t it smell? Feel odd to the touch? I tell you he checked