Philip R. Headings described this allusion in this way:
It is the shoring of these fragments, as well as the method and content of the poem as a whole, that is referred to in the next quoted fragment, from Kyd's Spanish Tragedy, "Why then Ile fit you." This half-line repays closer examination than it has generally received, for it emerges as a key statement of Eliot's purpose in The Waste Land.
The line is striking in both works. In Kyd's play it is spoken by Hieronymo, Marshall of Spain, to the king's nephew Lorenzo and to Prince Balthazar of Portugal, the murderers of Hieronymo's son Horatio. In a war between their countries Balthazar, before the beginning of the play, had first killed Don Andrea, the lover of Bel-imperia, and then been defeated and captured by Horatio. When Bel-imperia then fell in love with Horatio, the envious Lorenzo and the lustful Balthazar treacherously murdered him. All this is secretly known to Hieronymo and Bel-imperia, but, since they dare not appeal to the villains' royal relatives for justice, they swear to help each other obtain revenge. At this juncture the murderers approach Hieronymo, who has previously entertained the court with a dumb show, to ask him a favor:
LOR[enzo]. But now, Hieronymo, or never,
We are to entreat your help.
HIER[onymo]. My help?
Why, my good lords, assure yourselves of me
For you have given me cause - ay, by my faith,
BAL[thazar]. It pleased you, at the entertainment of the ambassador,
To grace the king so much as with a show.
Now were your study so well furnished,
As, for the passing of the first night's sport,
To entertain my father with the like,
Or any suchlike pleasing motion,
Assure yourself, it would content them well.
HIER[onymo]. Is this all?
BAL[thazar] . Ay, this is all.
HIER[onymo]. Why then, I'll fit you; say no more.
Hieronymo goes on to tell them that he has found again a tragedy he wrote when young, and he promises to present it if they will act in it, assuring them that "it will prove most passing strange, and wondrous plausible to that assembly." He relates the plot, which reproduces essentially, though not too obviously, the relationships existing among themselves. Each of the actors, he says, must speak his part in a different language so that the audience (chiefly their fathers) shall catch the true meaning of the play. To Balthazar's protests that they will not be understood, the Marshall replies,
It must be so, for the conclusion
Shall prove the invention and all was good.
And I myself in an oration,
And with a strange and wondrous show besides,
That I will have there behind a curtain
[the body of his murdered son, Horatio]
Assure yourself, shall make the matter known.
And all shall be concluded in one scene,
For there's no pleasure ta'en in tediousness.
Like Hamlet, Hieronymo has feigned madness to avoid alerting their fears; unsuspecting, they agree to humor him ("Hieronymo's mad againe") by acting the parts as he asks. When they inquire who shall take the part of the murderer, he replies, "0, that will I, my lords; make no doubt of it. / I'll play the murderer, I warrant you, / For I already have conceited that." He carries out his promise to the letter when the play is presented, murdering them on stage before their fathers' eyes; and malevolently but heartbrokenly he reveals the true roles they have played.