The two principal male characters of The Shadow of a Gunman, Davoren and Seumas, spend much of their time in philosophical debate, and also in criticizing their own countrymen. This is in spite of the fact that both consider themselves Irish patriots. Seumas complains,

Did anybody ever see the like of the Irish people? Is there any use of trying to do anything in this country?

The two men quote poetry to each other: Davoren repeats the phrase,

Ah me! alas, pain, pain ever, for ever!

Seumas immediately identifies this as from Shelley's Prometheus Unbound. The same line is quoted at the conclusion of the play, when both men are in a state of self-recrimination over their failure to act at the moment when courage was required. It is also emblematic of the history of Ireland under the English.

The allusion to the play's title comes at the end of act 1. Davoren is a man who appears to be an IRA operative (see the summary of the play in eNotes) and is looked up to by the others in the neighborhood because of this. Even Mr. Grigson, another resident of the tenement in which Davoren and Seumas live, tells him,

If you're ever in trouble, Mr. Davoren, an' Grigson can help—I'm your man. . . .

Yet Grigson is an Orangeman (a Protestant). In this same scene in act 2, Grigson declares,

Here's to King William, to the Battle av the Boyne!

The outcome of this battle for Ireland, in 1690, was that what is known as the Protestant Ascendency was confirmed: the legalized supremacy of the Protestants and oppression of the Catholic majority that was to continue another 230 years. This episode in the play is important because it reveals the high standing that Davoren holds with those who know him, in spite of his ultimate failure to do anything constructive.

The young woman, Minnie, who is attracted to him believes Davoren to be a "gunman on the run." But at the close of act 1 Davoren says to himself,

But Minnie is attracted to the idea, and I am attracted to Minnie. . . . And what danger can there be in being the shadow of a gunman?

The first quote above, Seumas's disapproval of his own people, ties into Davoren's reflections on himself. He ends up wishing to avoid personal danger. In act 2, when a raid on his building by the British is imminent, Davoren clearly panics. He searches for a letter that had been given to him, addressed to "the gentlemen of the Irish Republican Army," in order to destroy it before the British find him in possession of it. A bag filled with explosives that had been left in his flat is taken away by Minnie, who is arrested when found with it and then shot dead. Earlier she has had Davoren type her name, along with his, on a sheet of paper. This, if found on her, could also have been a danger to Davoren. But it is evident that he'll be safe for the time being. Mrs. Grigson gives a description of what has occurred:

Oh, it was horrible to see the blood pourin' out, an' Minnie moanin'. They found some paper in her breast, with "Minnie" written on it, an' some other name they couldn't make out with the blood.

This is symbolic of Minnie's sacrifice for Davoren. By removing the explosives from his flat, she has saved him, and her blood has expunged his name on the sheet of paper that could have linked him to her.