Ninth UK Story Arc " Normal routine aboard the starship " Enterprise " , cruising through the Sigma Draconis group to locate and contact new planet s . But suddenly , the whole craft was flung into shocked chaos ! " Summary . While exploring the Sigma Draconis System , the " Enterprise " suddenly comes to a complete halt . Recovering from the jolt , the bridge crew try to get their bearings , and Doctor McCoy and Nurse Chapel escort an injured helmsman Sulu to sickbay . Deflector s and video - scanners not functioning , Spock looks out of a porthole , only to see empty darkness . Frustrated , Kirk fires booster rocket s , but they don ' t respond either . Spock uses the atmospheric analyzer and discovers that the ship lies at the bottom of a sea . Shocked and perplexed , Kirk and Spock obtain pressure suits and go outside to investigate . The airlock floods with liquid , and a variety of sea creatures confirm Spock ' s readings . Kirk is attacked by a giant sea monster . Spock draws a phaser , but it doesn ' t work while submerged . The monster bites onto Kirk , and since there is a partial vacuum in its mouth , he is able to phaser - blast the beast , freeing himself . The two men then quickly get back on board the " Enterprise " . Spock analyzes the liquid in the ocean , and learns that it has a previously unknown chemical composition , heavier than water . This is why the ship did not simply float to the surface . Uhura reports that the body of liquid isn ' t limited to a local area , but composes the entire planet . Kirk muses that the ship ' s deflectors must have parted the substance enough to let the ship in . As the crew discuss the situation , they hear a knock on a porthole window . The ship is surrounded by " fish - men " , who promptly tow the " Enterprise " to their nearby city . They retrieve industrial tools from their city and attempt to penetrate the hull of the ship . Rather than let them drill , Kirk and Spock don their pressure suits and go outside to talk with them . The fish - men accuse the " Enterprise " of intruding , and ask where they came from . Kirk attempts to explain , but the fish - men reject the explanation as nonsensical and apprehend Kirk and Spock . Inside the city , Kirk and Spock manage to escape , but Spock is recaptured . Back on the " Enterprise " , Kirk has Scott assemble a raiding party , armed with knives , spears , and clubs . The team frees Spock and Kirk steals a freeze - gun from one of the fish - men . This inspires Kirk to press on the attack . He reasons that if they capture a large enough " freezer " , they can encase the " Enterprise " in ice and float it back to the surface . The fish - men immediately prove Kirk ' s prediction true , as they return with a tank equipped with a freezer . Kirk uses his freeze - gun to create a wall of ice , separating the tank from the fish - men reinforcements , and the raiding party easily takes over the tank . The raiding party are sent back to the ship , and Kirk and Spock fire the freezer , coating the entire ship . The two swim quickly to the surface in the ship ' s wake , and Scotty activates the force deflector s , shattering the ice . The men scramble aboard , and the " Enterprise " blasts off into space . Memorable quotes . " " This you won ' t believe ! We ' re under an external " liquid " pressure . . . thirty tons per square foot ! Captain . . . We . . . We ' re at the bottom of the sea ! " " " " Fish - men ! So there ' s more to this planet than monsters ! They must have intelligence . . . look at their clothes ! " " " " This is the captain speaking ! Now hear this ! We appear to have been captured by the intelligent inhabitants of this place . For the moment there will be no retaliation . . . " " " " You didn ' t tell the crew we can ' t retaliate , captain ! " " Background information . Publishing history . None of the UK weekly stories had titles . Each installment was two pages in length .