Hugh doesn't refuse your aid this time, instead telling you he's 'gonna end this' and requesting you back him up.  He's still trying to find that Purrloin, of course.

Battle: Team Plasma Grunt and Team Plasma Grunt (2320 Poke)
Opponent A: Koffing Lv 29, Watchog Lv 29
Opponent B: Grimer Lv 29, Raticate Lv 29
Hugh: Starter (evolved once) Lv 33, Simi(Sage/Sear/Pour, whichever has advantage against his starter) Lv 31

Hugh's a bit worse off than Cheren, if only because some of his options (notably Pignite) suffer recoil when using their strongest attacks and neither of the pokemon you're most likely to see him use have the impressive defenses that Stoutland does.  Still, he's likely higher level than you and using strong attacks, so this battle should similarly end with the Plasma G Grunts lamenting their inability to defend the Plasma Frigate.

With Team Plasma's goons defeated, there is much lamenting (on their part) and Hugh, satisfied, tries to start grilling Team Plasma for information.  Cheren agrees that this is time to question the criminals, as he wants to know a few things also.  Before the two can start getting answers, though, a gray-haired man in a somewhat piratey outfit shows up.  Cheren groans over the man's arrival, noting him as the man who was found two years ago shivering away in Driftveil's cold storage unit.

Identifying the Sage Zinzolin, Cheren insists the man tell him what the intent of the ship is.  Zinzolin ignores the question, instead declaring that the dragon pokemon will be used again and this time Team Plasma -will- control the Unova region.  Shouting that you won't be allowed to do as you please, Zinzolin calls out the Shadow Triad to evict you and your friends from the ship.

The ninja begin to protest something, but the sage cuts them off and insists they throw you, Cheren, and Hugh out of the ship.

Given no choice, you three are immediately moved to the dock, and the Plasma Frigate vanishes.