Oswald speaks with Regan. She asks him if Albany’s forces have been deployed. He acknowledges it, but says that Goneril actually leads them: “your sister is the better soldier.” He then discloses that he has a letter for Edmund which he must deliver. Regan suggests that Edmund has taken after Gloucester to kill him, as they realize that, alive, he “moves all hearts against us.” She wants to see the letter, attempts a little seduction, but Oswald refuses. She then declares that she is free — that Goneril was obviously flirting with Edmund, but she, Regan, is the more convenient match. She sends Oswald off with a promise of some reward if he happens to find and kill Gloucester. He responds ambiguously—that if he should encounter Gloucester, his real loyalty would be revealed—and leaves.
ACT IV. SCENE V. Location indeterminate.
Enter Regan and Steward
REGAN But are my brother’s powers set forth?
OSWALD Ay, madam.
REGAN Himself in person there?
OSWALD Madam, with much ado. Your sister is the better soldier.
REGAN Lord Edmund spake not with your lord at home? 
OSWALD No, madam.
REGAN What might import my sister’s letter to him?
OSWALD I know not, lady.
‘Faith, he is posted hence on serious matter.
It was great ignorance, Gloucester’s eyes being out, 
To let him live. Where he arrives he moves
All hearts against us. Edmund, I think, is gone
In pity of his misery to dispatch
His nighted life, moreover to descry
The strength o’th’enemy. 
OSWALD I must needs after him, madam, with my letter.
Our troops set forth tomorrow. Stay with us.
The ways are dangerous.
OSWALD I may not, madam.
My lady charged my duty in this business. 
Why should she write to Edmund? Might not you
Transport her purposes by word? Belike—
Some things, I know not what—I’ll love thee much.
Let me unseal the letter.
OSWALD Madam, I had rather— 
I know your lady does not love her husband,
I am sure of that. And at her late being here
She gave strange oeillades and most speaking looks
To noble Edmund. I know you are of her bosom.
OSWALD I, madam? 
I speak in understanding. Y’are, I know’t.
Therefore I do advise you take this note.
My lord is dead. Edmund and I have talked,
And more convenient is he for my hand
Than for your lady’s. You may gather more. 
If you do find him, pray you give him this.
And when your mistress hears thus much from you,
I pray desire her call her wisdom to her.
So, fare you well.
If you do chance to hear of that blind traitor, 
Preferment falls on him that cuts him off.
Would I could meet him, madam, I should show
What party I do follow.
REGAN Fare thee well.