Cheese, obviously.

[FlamingDeth]

That <i>is</i> what he was thinking about, you know. Said so himself.

[Mercury_Alex]

So how does cheese fit into an evil scheme? Give the heroes poisoned cheese? Nope, that wouln't work, one night at the inn heals them from it instantly.

[Xardion]

Actually, that wasn't the idea. The joke is that he comes up with this ultimate plan, but his train of thought is broken by Tina suddenly coming over the intercom announcing the unrelated arrival of his cheese. This interruption causes him to forget that he had just come up with an ultimate plan. Hence the plan is foiled even before it gets a chance. We'll never know what that plan was, but let me assure you, it was a good one...

[Lord McBastard]

But did this plan involve cheese? Ah ha, that is the ultimate question.

I got nothing...

*hangs his head in shame*

[Mercury_Alex]

In other words, you never thought of a master plan, since you didn't need it in the comic.

[Moonstone Spider]

Unless. . . he came up with a plan so good he decided to use it in real life and changed the comic to not give away what his plan is.

[Chrono_Catfish]

So then... I'm one of the only people who got that joke instantly?

...

...

GUNCHEESE!

[Moonstone Spider]

I guess it was too subtle. Or nobody else has come to post here since I made the joke.

[FlamingDeth]

...or all of the above!