I awoke to a throbbing head and Lyra’s concerned face shifting into focus. The bell from the engine order telegraph signaled that were in emergency full reverse. I inquired about our condition. Gyro reported that we had been pulled off course.
Once the ship righted itself and the turbulence outside dissipated, we saw the source of the strange powerful current – it was the feeding vortex of a monstrous copepod, the same species as the one we had seen from a distance. This one had evaded our efforts to spot such navigational hazards.
The monstrous crustacean filled the forward windows, drawing everything around it into its mouth. The only silver lining to being trapped in its feeding vortex was the opportunity to observe the copepod’s fan-like mouth parts terrifyingly close up. These fan-like appendages, beating furiously, created a current in the surrounding water that drew in a variety of single-celled organisms, such as algae cells. Countless green protozoa tumbled past our windows in a steady stream, disappearing into the copepod’s mouth. Due to the monster’s translucent exoskeleton we had a fascinating view of its well-packed gullet and the microorganisms digesting slowly in its stomach. We were safe for the moment, holding fast against the feeding current, and felt fortunate to not find ourselves in the same predicament as the tragic phytoplankton.
I glanced at the engine temperature gauges, and found it troublesome that the levels were quickly rising. Back in the engine room Barron was coaxing extra power from his engine to hold our position against the current, but the strain on the engine was beginning to show. A moment later came the call from the engine room I had been dreading.
“Skipper,” came the voice of our Engine Master over the voice pipe. “The combustion chamber is overheating. I can’t pump water through it fast enough to lower the temperature. We need to break out of this current and let the engine cool down, or it’s going to seize.”
Lyra looked up from her field journal, her face was animated: “Remember our observations from earlier, and what happens when something larger than the animal’s normal food gets caught in the its vortex fans? The animal stops to remove the object.”
From his station at the ship’s wheel an excited Gyro offered a suggestion. “Skipper, we can use hydro cohesion! At this scale, the surface of an air bubble is just a ball of surface tension. It might as well be a solid object. If we can make a nice big air bubble it might make that beast pause for a few seconds.
“Barron,” I called through the voice pipe, “execute an emergency purge of our CO2 holding tank! “
“Aye, skipper,” he called back.
The deck lurched slightly as the gas emptied from the ship, momentarily throwing off her trim. Through the windows an undulating bubble emerged from beneath the Cyclops and was caught in the vortex, whirling away. It fell toward the copepod’s mouth. We didn’t wait long to see if our plan had succeeded. Our CO2 bubble lodged like a boulder in the copepod’s fan-parts. The appendages halted.
I shouted into the voice pipe: “Engine master, full ahead! Pilot, get us out of here!”
A few seconds later, the copepod reversed its fan-parts, dislodging the bubble. As if nothing had happened it resumed its feeding current – but by then we were on our way, and safely out of range of its deadly vortex.