McHale and the Crew are enjoying some fun in the sun, with some of the local Italian girls, at a little beach, near their compound, when along comes Colonel Harrigan, catching them in the act. McHale explains that he and The Boys were just trying to boost civilian morale, and Harrigan smilingly tells them to enjoy themselves, but, as he walks away, to quietly tells Lieutenant Lucas that he intends to see that McHale and his Crew vacate the beach, so that he and Lucas can take it over, for their own enjoyment.
Later, in his office, Binghamton is enjoying some fun in the sun, himself, though it's an artificial sun, in the form of a sun lamp. Harrigan soon barges in, to discuss some certain charges that Binghamton has leveled against McHale and his Crew. Harrigan argues that due to such charges, and the fact that he has the 73 Crew living in such deplorable conditions, has caused them to lose their respect for their Captain. Harrigan warns Binghamton that General Bronson is due, soon, to check up on the morale of Binghamton's men, and that, if The General isn't pleased, he's likely to re-assign Binghamton to a very unpleasant location, in North Africa. Harrigan suggests that Binghamton move McHale and his Crew into his own building, an idea that Binghamton isn't crazy about. But, fearful of reassignment, he orders Carpenter to prepare the 73 Crew's new quarters in the east wing of the City Hall building.
Meanwhile, at the wine cellar, McHale and the guys are relaxing, after their hard day on the beach. But, Christy soon comes in with a red alert that Binghamton is on his way, so they scramble up the steps, toward their compound. Carpenter and Binghamton soon arrive, at the deserted compound, but McHale and the guys soon arrive, in a hurry. McHale explains that he'd had his Crew out on a sprint through the woods, for exercise.
Binghamton immediately begins to lay it on thick, and McHale knows that The Captain is up to something, and he's even more suspicious, when The Captain tells them that he's moving them into the city hall building, where they'll be much more comfortable, and urges them to start packing, immediately, for their big move.
Later, in their new digs, McHale vows to foil Binghamton's plan – Whatever it may be – And get them back to their old base, by the following day, and comes up with a quick plan to ensure that they accomplish their goal. They simply make nuisances of themselves, and The Captain will have no choice but to send them back to their old base.
That night, Parker begins with some practice on his bass drum, waking Binghamton from a sound sleep. Then, all of the rest of the guys come in, and make a lot of racket with a pillow fight. At first, Binghamton is pretty upset, but, when he remembers that he must stay on their good side, he joins right in on the pillow fight.
The following day, during an elegant breakfast, in The Captain's dining room, the phone rings. Binghamton answers, and Fuji is on the other end, disguising his voice, pretending to be a British Admiral, and friend of McHale's. Binghamton turns the phone over to McHale, and, after Fuji confirms that he's talking to the Skipper, he tells McHale that Harrigan had double-crossed them, so that he could take over their beach for his own private beach parties. McHale is pretty upset about that, and promises 'The Admiral' that they'll be right over to see him.
After getting Binghamton's permission, McHale and the guys leave. No sooner are they out of sight, than Carpenter rushes in, frantically trying to tell The Captain some news. But, before he can get it out, the phone rings.
Binghamton answers, and it's General Bronson. The General is trying to locate Harrigan, and Binghamton tells him to try the nearest bar, but The General isn't amused. Binghamton then goes on to say that he's moved McHale and the 73 Crew into his building, and that they're all getting along just fine. But, the General could care less about McHale's living arrangements, and lets on that he knows nothing about the morale inspection, nor any transfer to North Africa.
After Binghamton hangs up, Carpenter tells The Captain that he'd seen Harrigan on the beach, having a party with a couple of Nurses. Binghamton is furious about the situation, and vows to get even with Harrigan, by giving him a "Scare he'll never forget".
Meanwhile, at the very same time, back in the wine cellar, McHale makes that very same vow, as the guys are all getting dressed up in German uniforms, and Fuji loads their weapons with blank ammunition. McHale and the guys leave, immediately, to put their plan into action, but, little do they know that Binghamton and Carpenter have a very similar plan.
Later, as the Captain and Carpenter – Now, also dressed in Kraut uniforms – Sneak up on the beach, they see Harrigan and Lucas living it up with a couple of Nurses. Then, McHale and Parker come roaring in, in a jeep, breaking up the party.
McHale jumps out, .45 in hand, and tells the startled Harrigan that the woods are full of Germans, and that they'd better run for it, or they'll be in big trouble. Suddenly, the sound of gunfire is heard, in the woods, nearby, as Gruber and the guys begin their act. As Harrigan and the Nurses take cover, McHale and Parker crouch, next to the jeep, and return fire, while Binghamton and Carpenter – Thinking that it's a real Kraut raid – Make a run for it.
Harrigan and the Nurses make a run for it, as McHale and Parker keep up the act. Meanwhile, Binghamton and Carpenter make their way to a large log, and crouch behind it, while Gruber and the guys crouch on the other side of the same log. When Binghamton and Carpenter slowly rise up, and peek over the log, they find themselves looking at Gruber, Tinker, and Willy, and both sides run, screaming. Gruber and the guys hide, not far away, thinking that Binghamton and Carpenter are real Jerrys. Soon, along come McHale and Parker, and Willy tells them of the 2 Krauts they encountered. McHale gives the order to go after them, and, when they look around, they see the 2 'Germans' dump their weapons, and run for it.
McHale and the guys give chase, and run them down, in the middle of their compound. When they see that it's Binghamton and Carpenter, Binghamton explains that he and Carpenter were on a secret mission, and then tries to accuse McHale and the Crew of defecting to the enemy. But, McHale explains that they, too, were on a secret mission, and adds that they were very successful with their objective: Getting Harrigan off their beach. When McHale tells The Captain how Harrigan ran scared, when he thought the Germans were attacking, Binghamton adds that he'd love to have seen "That sniveling, conniving, phony".
Just then, Harrigan – Having forgotten his lucky swagger stick – Comes along, and witnesses the whole scene. McHale and the guys try to continue their German act, but it's too late. Harrigan is onto them.
"Ohh, I can hardly wait to speak my little piece, at the court martial." Says Harrigan.
"And, I can hardly wait to hear those two Nurses speak their little piece…" says McHale, "…When we call them in as witnesses!"
Harrigan knows he's been had, but before he has a chance to protest, who should come along, but General Bronson. Harrigan pulls his .45, and tries to make it look like he's taken some German prisoners, and Bronson falls for it, until he sees that one of the 'Germans' is Binghamton. The General, of course, wants an explanation, and McHale, thinking quickly comes up with one, explaining that they were staging an "Enemy mock invasion", and that The Captain had invited Colonel Harrigan, as an observer.
Bronson swallows the story, and expresses his approval, and soon leaves. After The General and Harrigan are out of sight, all breathe a sigh of relief. Binghamton then firmly states his intention to move McHale and his 'Pirates' back to their usual base, and get them out of his building, immediately, which draws a hearty 'hooray' from the guys.
Just then, a flight of American planes swoops in, and Parker foolishly waves the German flag at them. The planes begin to fire on the group of German-uniform-clad Sailors, and the guys all run for cover, as Binghamton frantically strips down to his shorts.