How we cite our quotes:
Which is the poison to poison her, prithee? (4)
We get into the nitty-gritty of this poem right away. We're not even into the second stanza of the poem, and already we're hearing about poison and murder. We don't know yet that there's a revenge plot, but that's what Browning is setting us up for. He wants us to know that there's dirty work afoot. He uses this fourth line like a hook to pull us into the poem and get us thinking about why the speaker would want to kill someone.
While they laugh, laugh at me, at me fled to the drear
Empty church, to pray God in, for them!—I am here. (7-8)
We think there's a devilish little twist at the end of the eighth line. Our speaker is about to turn the tables on her cheating man and his girlfriend. She thinks that they think that she ran away to cry and pray. Instead, she's plotting revenge. When she says "for them!—I am here," she means that she plans to wipe the girl out and make the guy wish he had never laid eyes on her. She's taking control with this plot, refusing to get walked all over, and she declares it out loud. Revenge is her way of taking the wheel. Drat, we keep finding ourselves kind of liking this murderous gal!
Let it brighten her drink, let her turn it and stir,
And try it and taste, ere she fix and prefer! (27-28)
We think this line is really key. It's not just the revenge that's the goal. It's the delicious plot itself, the slow way it unfurls. Our speaker doesn't just want this other woman dead, she wants to be able to watch it happen. Again, we think this revenge thing is partly just about being in control. She's had something taken away from her, and now she wants to be the one who can take something away, who has a deadly secret of her own. She wants to watch the happy couple enjoy themselves, not knowing the terrible things that are about to go down.