He can't even come into the house without getting that thing pointed at him? Link stares up at him for a moment, taking in what he can see - Duo holding Sheik, neither of whom seem right in the head, Duo aiming a gun at him, Duo's weird behaviour like scaring Sheik earlier.

Okay. Something is wrong with Duo, then, and he has to get him away from Sheik. Now.

The sword stays in its sheath for now, but Link's hand is ready to grab it at a second's notice as he takes a few steps closer. "Duo, get away from him," he says, trying to sound calm and in control but the words coming out more like a growl. "You're not... you're not yourself. I'll take care of Sheik myself."

And he sets a foot on the bottom step.