Ambush (The Enterprise Incident)

Enterprise Medical Log, stardate 5027.3. Doctor Leonard McCoy recording. I'm concerned about Captain Kirk. He shows indications of increasing tension and emotional stress.
[Bridge]
CHEKOV: I have completed the assignment, Captain. A theoretical incursion into 
KIRK: Yes, Mister Chekov. I can read, and as usual your theoretical evaluations do not tally with mine. Return to your duty and I'll let you know when your work is satisfactory. 
KIRK: Mister Spock. Full sensor scan of the region, please. 
SPOCK: I did give a full report 
KIRK: Yes, Mister Spock, that was the past. I'm concerned with the present. Or is it becoming too much for this crew to present me current information? 
SPOCK; No, sir. Compliance presents no problem. 
KIRK: Then, Mister Spock, comply. 
SPOCK: Sensor scan to one half parsec. Negative, Captain. 
KIRK: Very well. 
MCCOY [OC]: I can find no reason for the captain's behaviour, except possibly that we've been on patrol too long without relief and diversion. He has resisted all of my attempts to run a psychological profile on him. 
SULU: Maintaining course and speed, sir. 
KIRK: Change course. Come about to one eight five, mark three. 
SULU: But, sir, that'll lead us directly into the Romulan Neutral Zone. 
KIRK: Yes, very perceptive, Mister Sulu. I know where the course change takes us. Execute. 
SULU: Aye, sir. 
SPOCK: Increasing sensor scan to one parsec. All scanners report clear. Nothing in our immediate vicinity. 
KIRK: Better and better, Mister Spock. 
SULU: Captain, leaving Neutral Zone. Now entering Romulan space. 
(Scott enters the Bridge.) 
KIRK: Very well, Mister Sulu. 
SCOTT: Lieutenant, when did the order come through? 
UHURA: Order? 
SCOTT: From Starfleet. The order to enter the Neutral Zone. 
UHURA: There's been no order I know of, Mister Scott. 
SCOTT: Surely the Captain couldn't be doing this on his own authority. 
KIRK: If you two have complaints, you can bring them out into the open. 
(A sinister shape appears on the viewscreen.) 
SCOTT: That's a Klingon ship! But it couldn't be, not in this area. 
SPOCK: Intelligence reports Romulans now using Klingon design. 
KIRK: Sound Red Alert. Man battle stations. Stand by main phasers. 
UHURA: Battle stations. All hands, battle stations. 
SPOCK: A second ship has appeared. (another one decloaks) Correction, there are now three. We are surrounded.