Dirk is definitely smarter than he looks, even when tipsy. Possibly moreso, with the booze slowing his trains of thought down to a speed where they're easier to analyze.

Thor looks slightly sheepish and defensive. "Kate said to take it with me."

Dirk flicks ash off his cigarette, and tries a bad Groucho Marx impression. "Sure, but what was it before it was a duck?"

"The postman." Thor says slowly, completely serious.