A K'normian trading ship was a type of shuttle built by the K'normians for the purpose of ferrying cargo and passengers. The ship's power was derived from fuel cells. In the cockpit, the pilot's console was at the front, with the engineering console to the left and the communications console to the right. The ship had no offensive capabilities.
A month later, the Enterprise was in pursuit of John Harrison, who had fled to the Klingon homeworld Qo'noS. After his ship suffered an unexpected warp core failure near the edge of the Neutral Zone, Captain James Tiberius Kirk was informed by Hikaru Sulu that the time to target was twenty minutes. If the Enterprise was detected in Klingon space, this could start an all-out war. The captain decided, instead, that he would take his first officer Spock, communications officer Nyota Uhura, and two security officers with him on a mission to Qo'nos. The five Starfleet officers, masquerading as K'normian arms smugglers, would travel on aboard the unnamed trading ship. Kirk estimated the mission would last two hours. In those two hours, the ship would travel to the planet, their target would be secured, and then the ship would return to the Enterprise. If all went to plan, they wouldn't be noticed by the Klingons. In his absence, Sulu was the acting captain.
As it happen, the craft was detected above a derelict city in the Ketha Province by a D4-class fighter. During the pursuit, the trading ship boosted its velocity by using all six of its fuel cells. When that didn't work to shake off the pursuing fighter, Kirk piloted the ship between two structures, resulting in minor hull damage. Soon after, the ship was surrounded by three fighters. The lead fighter ordered the trader to land. After the trader landed, there was an unsuccessful attempt at negotiations which culminated in a fight with casualties on both sides. With Harrison's aid, the fight went in the direction of Kirk's landing party. With Harrison voluntarily surrendering and being secured, the trader returned to the Enterprise. (Star Trek Into Darkness)
Background information Edit
Development of the K'normian trading ship began with the realization that a non-Federation craft was required to fill a place in the storyline of Star Trek Into Darkness. Remarked co-writer Alex Kurtzman, "We knew that for the mission that Kirk wants to go on to work, it couldn't be a Federation ship."  Editors Mary Jo Markey and Maryann Brandon described the ship as an homage to Mudd's ship in Star Trek: The Original Series. (Star Trek Into Darkness iTunes enhanced commentary) A concept illustration of the K'normian trading ship can be viewed here.
The production crew which worked on Star Trek Into Darkness constructed an interior and doorway of the K'normian trading ship. Exterior shots of the vehicle in the Enterprise hangar bay were generated by Industrial Light & Magic, whereas CGI views of the craft in the atmosphere of Kronos and on the planet's surface were rendered by Pixomondo. (Cinefex, No. 134, p. 84) Pixomondo Visual Effects Supervisor Ben Grossmann thought of the ship as basically "a little sparrow trying to take advantage of its size and move through little cracks and nooks and crannies and be a little more nimble [than the pursuing Klingon fighter]."