In the days after the Dunkirk evacuation in Second World War, recently commissioned Second Lieutenant Jim Perry (David Niven), a pre-war Territorial private soldier, and a veteran Sergeant Ned Fletcher (William Hartnell, of the British Expeditionary Force, is posted to the (fictional) Duke of Glendon's Light Infantry, known as the "Dogs", to train replacements to fill its depleted ranks. A patient, mild-mannered officer, he does his strenuous best to turn the bunch of grumbling ex-civilians into soldiers, earning himself their intense dislike.
The conscripts also believe that their sergeant is treating them with special severity; in fact, he is pleased with the way they are developing and has his eye on some of them as potential NCOs. Eventually. however, the men come to respect their officer.
After their training is completed, their battalion is shipped out to North Africa to face Rommel's Afrika Korps. Their troopship is torpedoed en route, and they are forced to abandon ship. Sergeant Fletcher is trapped by a burning vehicle sliding on the deck as the boat heels to one side, but is rescued by Perry and several of the men. The survivors are able to come aboard a destroyer and are sent to Gibraltar, missing the invasion.
When they eventually get to North Africa, the group is assigned to guard a small town. Perry appropriates a cafe as his headquarters, much to the disgust of the pacifist owner, Rispoli (Peter Ustinov). When the Germans attack, Perry and his men fiercely defend their positions, aided by Rispoli. At one point, the Germans invite them to surrender, with their response: "Go to Hell!"
The besieged British soldiers mount bayonets and join other surviving units in advancing on the enemy, hidden in the smoke from explosions. At home, the veterans from the "Dogs" appreciably read about the men's bravery.
The Way Ahead was written by Eric Ambler and Peter Ustinov and directed by Carol Reed. The three had originally produced the 1943 44-minute training film The New Lot, which was produced for the Army Kinematograph Service. The Way Ahead was an expanded remake of their earlier film, this time intended for a commercial audience. The two films featured some of the same actors, including John Laurie, Raymond Huntley and Peter Ustinov, at the time, only 23 years old.
The driving force behind the film was David Niven, a 1930 graduate of Sandhurst, who, was at the time, a major in the British Army working with the Army Film Unit, and later, served in Normandy with GHQ Liaison Regiment. Niven served as the executive producer on The Way Ahead.
The last scene in The Way Ahead shows the soldiers advancing in a counter-attack. Instead of the film ending with the words "The End", it concludes with the more uplifting "The Beginning", an attempt to galvanize support for the final push in the war effort.
In the United States, an edited version of The Way Ahead with an introduction by journalist Quentin Reynolds, was released as Immortal Battalion.
According to trade papers, The Way Ahead was a success at the British box office in 1944. In 1945, The Way Ahead as the Immortal Battalion was listed as one of the Top Ten Films by the USA National Board of Review.
As the Immortal Battalion, film critic and historian Leonard Maltin, noted: "Exhilarating wartime British film showing how disparate civilians come to work together as a fighting unit; full of spirit and charm, with an outstanding cast, and fine script by Eric Ambler and Peter Ustinov."
The final scene of the advancing soldiers was imitated for the closing credits of the long-running BBC sitcom Dad's Army. John Laurie appeared in both productions and his performance in the sitcom credits, mirrors this film.
As of January 2016, The Way Ahead has received a rating of 7.1/10 stars on IMDB and a tomatometer rating of 100% and an audience score of 71% on Rotten Tomatoes, with many viewers praising the cast's performance and the film's sense of authenticity.