Basically, this plot is a marker for those who'd support Wulfenbach to make sure that Gil isn't overwhelmed by the sheer numbers of Agatha + company.
Justin: Yes, that sounds right. It's a delicate balancing act, but I concur that we need to deal with it. Indeed, we need to make sure that someone like DuPree is present, to keep Gil from falling in with Agatha too easily himself.
As a side note: I don't think Klaus would rely too heavily on Jaegers for this security; Klaus seems well aware that they still have strong Heterodyne loyalties - in fact, if he's bright (which he is) he'd probably try to guard against a sudden and undesirable mass transference of Jaeger loyalties (not necessarily by having more force there, that's terribly unsubtle - more likely by setting up the situation so that the Jaegers defecting en masse would work against their own interests.) Justin: true, but I think we should construct the scenario so that Klaus didn't know Agatha was involved. That eases a lot of problems, and makes it more plausible that he didn't come himself.
Justin 1/7: In practice, this plot boils down to, "Klaus sent Gil to figure out what's going on". This is Gil's only active plot, and it's intentionally vague -- he is to ascertain what's up with the Hidden Castle, and make sure that it doesn't present a threat to the empire. Its membership mostly corresponds to the Wulfenbach Envoys faction, but not quite -- the faction is more about loyalties, whereas the plot is more about who actually came with Gil.
The Wulfenbach group is traveling "incognito" -- that is, looking like an ordinary noble and his retainers, rather than the usual Wulfenbach army. This is mainly because he's trying to show his father that you don't have to resort to overpowering force in all circumstances. But he's not stupid, so he's brought the two deadliest members of his father's retinue with him, DuPree and Jenka. He does, of course, have a flying fort and a small army of Clanks, but they are a day's ride away at this point. (Does this make sense? If not, possibly Othar and crew brought down his airship, so he really is on his own.)
Characters In Game: DuPree Gil Jenka Wooster
All Characters: DuPree Gil Jenka Klaus Wooster