Allegedly sent to Germany as an American war correspondent, William Berner, who quickly wins the confidence of the German military brass, is really a British spy. Then, he learns that as part of the new Allied strategy, the house where he is staying must be bombed. Choosing to ignore the fact that the Germans are his enemies, William saves the lives of the three German women who are in the house with him, but before the British high command can question his loyalty, he gives up his life for England after he fights his way into Pit Forty-Three, a German stronghold, and then wires the British to bomb it, leaving himself no time to get away.—Pamela Short

"Shell Forty-Three" is a unique narrative of cunning in the European war. It concerns the adventures of a young man of mystery who possesses papers which prove him to be the correspondent of a big American newspaper; others establishing him as a German secret service agent, and still others vouching for his commission as a lieutenant in the English army. The secret of his mission is not divulged until the last scene, when the veil of mystery enshrouding his identity is lifted and he is shown in his true light. In many of the big scenes of the story, virtually all the accoutrements of modern warfare are shown in action and as an elaboration of the wonderful spy system employed by all the contending forces in any great national struggle, the story is particularly interesting.—Moving Picture World synopsis