Wrex tells Heyoke that if Mosphet falls, so does the republic, he serves the wolves not because he loves them, but because this is the last country, he's trying to keep everything in one piece, he's just trying to save as many people as possible, which is what he always wanted. Heyoke replies that if the wolves are going to live they will have to do it themselves. He specifically calls Serinth a great killer but a terrible diplomat.
Wrex asks Heyoke how she could have planned this. Heyoke sort of laughs and says she's had a thousand lifetimes to plan it. (Or maybe it is Serinth talking to him right before Heyoke comes up, that makes more sense, anyway, Wrex doesn't understand.)
At some point when Serinth first visits him (before Heyoke enters and she leaves) Majordomo notes that he's getting pretty fed up with being behind bars (or something like that, a final hint that he was Wrex in Rabbits of Styx before Heyoke reveals it to the audience).