He said he would not ransom Mortimer;
Forbade my tongue to speak of Mortimer;
But I will find him when he lies asleep,
And in his ear I’ll holla ‘Mortimer!’
I’ve remarked before that I’ve found some of Shakespeare to be tough going and this first act of Henry IV, Part I was a good example. I’ve managed to divine that there are a bunch of wars going on and the king is at odds with some of his nobles. Many prisoners have been taken during the conflicts and the king is demanding that they be turned over to him. The nobles don’t dig it and it appears that a rebellion is brewing.
In the meantime, the prince and his pal Falstaff seem to be engaged in some comparatively trivial pursuits, planning to play a prank on a few of their pals who are plotting a robbery. Or something like that. I admit that I didn’t completely get the gist of all this but I think I'm close.