Black wind

said.
    “Our Fu Manchu friend, Tongju, was most insistent,” Summer replied grimly. “He even prevented one of the guards from shooting you so that we could wallow down here together.”
    “I must remember to send him a thank-you card.” Dirk looked down and saw that the water was now sloshing around his rib cage.
    “Water’s rising pretty fast.”
    “We’re near the mouth of the Han River, so there’s plenty of tidal surge at work.” Summer gazed fearfully at her brother. “I’d estimate that the water level has risen over a foot in the last hour.”
    Seeing the despair in his sister’s eyes, Dirk’s mind engaged in high gear to determine a means of escape. “We have another hour and a half, tops,” he calculated.
    “I just remembered something,” Summer said, crinkling her brow. “I’ve got a small nail file in my side pocket. Might be like trying to kill a pterodactyl with a flyswatter, but it might help.” “Sure, toss it over,” Dirk replied.
    “This one mooring ring looks pretty mangy,” she said, tugging at her left wrist. “If I could just get one hand free.”
    “Maybe I can help.” Dirk slid his legs toward Summer, leaning his torso at an angle along the concrete blocks for support. Raising one leg, he slid his foot along until the sole of his shoe met up with the face of the protruding iron. Applying as much pressure as he could, he pressed his weight hard against the top of the metal ring.
    Nothing happened.
    Shifting his foot so that his heel was against the ring, he pushed once more. This time, the ring bent a fraction toward Summer. Jamming his weight repeatedly against the stanchion, he gradually forced the ring to bend over nearly ninety degrees.
    “Okay, I’ll need your help in pushing it back upright,” he said. “Let’s try it on the count of three.”
    Slipping his foot to the backside of the ring, he counted to three, then pulled his leg toward him. Summer pushed with her manacled hand and they gradually shoved the ring back to its original vertical position.
    “Well, that was fun,” Dirk said while resting his leg. “Let’s try it again.”
    For twenty minutes, they toggled the ring back and forth, the movement gradually becoming easier as the tensile strength of the old iron weakened. With a last strong kick by Dirk, the ring finally snapped off its concrete base, freeing Summer’s left arm. She immediately twisted her hand around and dug into the small side pocket of her silk jacket and produced the porcelain-handled nail file.
    “I’ve got the file. Should I try on the handcuff itself or the mooring ring?” she asked.
    “Go for the ring. Even though it’s thicker, it will be much softer to cut through than the hardened stainless steel handcuffs.”
    Using the small file like a hacksaw, Summer began grinding away at the base of the mooring ring. Working the file with any degree of accuracy beneath the murky river water and fading cavern light would have been a Herculean task for most, but Summer’s extensive diving experience gave her a leg up. Years of exploring and excavating historic shipwrecks in foul visibility had heightened her sense of touch to the extent that she could nearly tell more about a wreck from her hands than by her eyes.
    With some measure of hope, she felt the file cut rapidly through the outer layer of the rusty ring. Her confidence waned when the blade met up with the hardened inner core of the iron ring and progress slowed to a snail’s pace. The rising water was now level with her chest and the pending urgency unleashed a surge of adrenaline. Summer worked the blade back and forth as fast as she could muster underwater, gaining ground millimeter by millimeter. Taking quick breaks from sawing, she placed her hands on the iron ring and pushed and pulled it to weaken the metal. Alternating sawing and prodding with an intermittent gulp or two of river water, she at last broke through the ring and freed herself.
    “Got it,” she exclaimed with victory.
    “Mind if I borrow that file?” Dirk asked calmly, but Summer had already kicked and swum her way over and begun cutting into the ring grasping his right hand. As she worked the file, she mentally noted that it had taken her roughly thirty minutes to cut through the first ring and that the water level was now nearly to their shoulders. The water was rising faster than she anticipated and would be well above Dirk’s head in less than an hour. Despite aching fingers and