This series has never been particularly shy about the whole "webs within webs, plans within plans" political theme. It's a bit deus ex machina to have it play out like this specifically, but it is certainly believable if you take into account the whole shadow war background that's been explained in previous chapters. When everyone is secretly plotting against everyone else, it's not exactly unusual for events to take a wild swing towards the non-sequitur.
Perhaps unexpectedly, it also enhances the romance aspect. How much Graham the Hero actually cares about the MC is unknown as of yet, but it makes sense that he's so invested in her when she's the only person he can be reasonably certain isn't lying to him, manipulating him, or otherwise trying to backstab him.