Kirk, via communicator, to the location of the cloaking device. His signal is discovered and tracked, and Spock surrenders himself to the Romulan officers, but they are too late to prevent Kirk from stealing the cloaking device and returning with it to the Enterprise. Chief Engineer Scott attempts to adapt the Romulan cloaking device to the Enterprise while Ensign Chekov succeeds in distinguishing Spock's life signs from those of the Romulans. Both Spock and the Romulan commander are beamed to the Enterprise where Kirk gives the order to return to Federation space. The pursuing Romulans are ready to fire upon them as Scott successfully activates the cloak and the Enterprise vanishes before their eyes. The now-captured Romulan commander points out to Spock that any advantage the Federation gains from studying the new cloaking device model will be temporary, as before long the Romulans will learn to circumvent it. Spock admits that military secrets are the most fleeting of all. Production Writing D. C. Fontana based this story very loosely upon the Pueblo incident, in which a United States Navy ship and its crew were seized, and the crew held on charges of espionage for almost a year, after the ship allegedly strayed into North Korean waters. The first draft of the script had Spock "raining kisses on every square inch above the shoulder" of the Romulan commander but this was changed, at Leonard Nimoy's insistence, to the more demure finger caresses. Fontana has pointed out that the "raining kisses" scene was actually an embellishment by Gene Roddenberry—one of the few he applied to third season scripts—and that the original script submitted had only an embrace and kiss, with most of the passion being delivered by the Romulan commander. Originally, both Kirk and McCoy were disguised as Romulans and went aboard the Romulan ship to steal the cloaking device. This was dropped not only due to cost concerns, but because Robert H. Justman pointed out that having McCoy doing plastic surgery on his own ears would have stretched believability, and including a character to perform the surgery on both Kirk and McCoy would have required casting an additional role, further increasing the cost. Models In the remastered edition two of the three Romulan warships are actually Klingon craft, used in addition to the Romulan bird-of-prey seen in the episode "Balance of Terror". Although in production order the model was first used