When communications with the "Black Rook" patrol that was sent to get the location of a German big gun is suddenly cut off, Saunders and his men ("White Rook") go in to find out what happened. In a dye factory, they find the missing patrol all dead and a hidden German deserter. Saunders must decide if the prisoner lives or dies when the squad makes their escape.

On the frontline, the squad receives three new replacements straight from rear echelon duty in England. They are Gainsborough (a scared, overweight cook), Temple (an equally scared ex-ballet dancer), and Crown (a radio announcer whose cocky attitude masks his fear). Saunders reluctantly takes these newcomers on a dangerous recon mission and discovers that his survival depends on the ingenuity of these misfits.

Jeffrey Hunter stars as tanker Sgt. Dane, a man mad at the world, mad at the war, and mad at God. He's not too thrilled with Hanley and Saunders, either. During a German advance, Hanley and squad are cut off behind enemy lines. They are saved from an ambush by the appearance of Dane and his tank. But Dane’s recklessness and anger takes on a savage edge and they discover the secret he can’t live with: that he’s a failed priest now turned killer.

While in a French town, Hanley takes refuge in a church basement during a bombing raid. An unexploded bomb brings down heavy timbers that trap him beside the bomb, which is still timed to explode. Help arrives in the form of a British demolition expert who is suffering battle fatigue and is angry at Hanley for trying to pick up his girl at a local bar.

Pvt. Grady Long, Saunders' friend and the squad's B.A.R. (Browning Automatic Rifle) man, is killed. Kirby expects Saunders will give him the B.A.R., but Saunders decides to give it to the new man, Pvt. Delaney (Joe Mantell), a cook that had qualified on the B.A.R. in basic training. After Delaney is killed, Saunders finds his reasoning for giving it to him didn't matter.

A mission to retrieve downed wing commander Col. Jafko (Howard Duff) goes awry when Lt. Hanley's squad mistakenly shoots the messenger who delivered the pilot's whereabouts to them. A "Maquisard" truck driver transports them to the farm where French Resistance have hidden the wounded pilot, and where he has fallen in love with the farmer's daughter, Denise (Maria Machado).

Lieutenant Hanley is captured and interrogated. General von Strelitz (Albert Paulsen) takes him away for further questioning, but instead calmly kills his chauffeur and forces Hanley to replace him. The General refuses to explain what he's plotting, and Lt. Hanley doesn't appreciate the promotion to Kapitan in the Heer. Things get complicated when von Strelitz involves his daughter, Maria (Joyce Vanderveen).

Del Packer (Tab Hunter), a famous baseball star who was drafted into the army, is a replacement in the squad. While Kelly tries to make money by setting up a baseball game with a neighboring outfit, Billy—a devoted baseball fan—is awestruck by his hero. However, Packer has his own demons to fight, and while the others are too star-struck to notice that something may be wrong, Saunders isn't.

A worn out Sgt. Saunders must lead Sgt. Jenkins & his men into an area where he had already seen lots of casualties. Jenkins assumes Saunders is a bad soldier. All are killed except Saunders and Jenkins, who find themselves trapped in a new German command post. Jenkins wants to escape ASAP, then has a surprising change of plan.

A Frenchman with important information and Pvt. Temple (his last appearance in the series) are injured by a land mine. The squad takes refuge in a convent of cloistered nuns. Hanley was bringing a doctor, but he dies of a heart attack on the way. Saunders and Caje go into the village in search of another doctor, but have to take bold steps to get one.

In a flashback story, Sgt. Saunders recalls experiences around the D-Day invasion. This includes tales about Braddock, who won the pool for when the invasion would take place; Doc, who was reluctant to go into battle; Caje (called "Caddie" in this episode) who is accompanied by another Cajun; and Lt. Hanley, who was still a sergeant, and had little battle experience compared to Saunders. Following the landing, the men move inland to a farmstead held by a squad of Germans.

This is Braddock's (Shecky Greene) comedy episode. He is "appropriated" by tough-talking, overbearing Colonel Clyde (Keenan Wynn) as jeep driver. The Colonel insists on driving himself, and his reckless driving results in an accident. Braddock is captured by the Germans, who think he is a Colonel because he is wearing the colonel's coat. At first he resists, but Pvt. Braddock begins to enjoy the role.

After the battalion pushes the Germans out of a small French town, Pvt. Paul Villers (Chris Robinson) asks permission to look for his father, Emile, a French doctor. Villers was born in France but his mother, an American, took him back to the US. With Sgt. Saunders, Villers finds out some things about his father that he wasn't counting on.

Close friends D'Amato (Joseph Campanella) and Wharton (Frank Gorshin) become separated from the rest of the men when the platoon is ambushed by a German tank. D'Amato flanks and captures the armor and turns the machine gun on the supporting German infantry, but is gravely wounded. When the rest of the platoon reaches the position, it appears that Wharton single-handedly captured the German armor.

Taken prisoner, Sgt. Saunders is transported until the prisoners are freed by Resistance fighters. With the help of Annette (Micheline Presle), who provides ration coupons in exchange for a ride, they buy gasoline to transport the Allied soldiers to Paris. Annette resists providing further help when they reach Paris, but agrees to take in Saunders for a few nights. Her lover, Maj. Kurt Hoffman (Alf Kjellin), complicates things.

Thirteen-year-old French boy Gilbert Barole (Serge Prieur) wants to join the squad when he sees their glory after liberating his town. Told that he can't, he follows the squad anyway. When Lt. Hanley is wounded, Caje tells him to take Hanley back to town. They find the Germans have moved back in and are setting a trap. Gilbert must find Sgt. Saunders and tell him about the Germans. Gilbert discovers that soldiering is not all gallantry and glory.

The squad gets an amiable replacement from Georgia named Moseby Lovelace (Jonathan Bolt), who comes complete with a coveted, new pair of boots. Lovelace is eager to see action, but not interested in the ordinary work of soldiering such as digging foxholes and following orders. He has a hair-raising adventure on a night reconnaissance patrol, but handles it with aplomb.

Corporal Cross (Ben Cooper) is the newest addition to the squad. For once, the new man is a veteran, but he is tormented by a fatal mistake he'd made on another hill. That mistake has crippled him, stripping away not just his ability to fire a rifle, but also his ability to be a soldier. Although not part of the main plot, Dick Peabody has a very strong episode as Littlejohn.

Doc, Braddock and others take refuge in a French château owned by wealthy aristocrat Count de Gontran and his lovely daughter Gabrielle. The Count wants no part of them and orders them off the property, but a large German force moves in to use the château as an artillery observation post. The Americans are taken prisoner. The Count sees a kindred spirit in the seemingly cultured commander Major Richter, but doesn't realize that Richter wants the château's treasures—including Gabrielle.

PFC March runs into his wife, Lt. Amelia March, at a field hospital. He asks for a pass to spend time with her. While he is waiting for his pass, Kirby goes AWOL and ends up at the hospital. March must go out on a mission in place of Kirby.

Lieutenant Hanley and his men have just three hours to rescue an old man, pretty librarian, and 5 children from the Germans before the Americans bomb the building they are in.

While on a night patrol to take a prisoner, Sgt. Saunders and his squad discover an American lieutenant waging the war on his own and living in a cave.

When Lt. Hanley and the squad escape from a POW camp, Saunders is left behind. In enemy territory, his hands badly burned, Saunders weaves a treacherous path back to his own lines.

Saunders resents a cold-hearted, reckless photojournalist (Elizabeth Allen) who accidentally causes a town to believe they are liberated. When the Nazis move in and the resistance workers are exposed, she learns the seriousness of human suffering during war.

Lt. Hanley is pulled off the line and sent to London, where he is assigned to a secret mission to aid a French physicist to escape occupied France before the Gestapo captures him. Hanley once spent the summer in France at the family's home and is the only man the scientist will trust - especially since it has been discovered that someone in the French resistance is a double agent.

A young woman who cannot face the horrors of the war isolates herself in an idyllic garden which is unscathed by German bombs and refuses to leave. Saunders attempts to evacuate her before more Germans come.

Kirby is court-martialed, accused of desertion under fire by Sgt. Metcalf (Robert Culp). The potential sentence is death. As the trial proceeds, Sgt. Saunders and Caje try to gather evidence to prove his innocence. Conlan Carter, who plays Doc beginning in Season 2, appears here as an MP.

A never-say-die German stays behind after the German withdrawal to wage his own private war, aided by a beautiful but bitter Frenchwoman who has her own reasons to hate the town that her German lover terrorizes.

The squad discovers an orphaned baby in a barn, and must decide whether to bring the infant with them as they traverse through enemy territory en route to their own lines.

Saunders becomes one of the walking wounded and falls under the mercies of three broken souls more deeply wounded than he: a beautiful nurse, a doctor who has lost his nerve, and a driver who never had any nerve.

Rob Lawson (Dean Stockwell) joins the squad with the belief that his fate his sealed, and with a reputation as a one-man army. Hanley, Saunders and their men are worried that his reckless bravery will get them all killed.

Caje must deal with killing a Frenchman. He does this by turning his attention to the dead man's daughter, shirking his duty and worrying the squad. Sgt. Saunders must find a way to bring Caje back to reality before losing him. Saunders finds what he needs when the town is attacked by the Germans.