Find a phone to call someone, anyone who can help you. You can't help both Kwan and Charmaine, and God knows how much you have to.

From Create Your Own Story

You run in a frenzied haste and finally stop at the living room, seeing a phone. You rush forward and see another kid, about your age, trying to connect the phone to the wire. With him is a girl, tugging at her brother's arm. It seems like you, Kwan and Charmaine aren't the only ones in the house. You overhear the girl saying, "Where's Lucas?". The boy replies,"I suppose he's at where they keep the bodies.".

You could try diplomacy and...

Walk in there and try to explain the situation, you might save both Kwan and Lucas

Run in and try to fix the phone.

or, they might be trying to trick you, how many elder brothers go into a mansion while their youngest brother went into a body cellar?

Grab a chair and run into the room.

Throw a potted plant at them

Throw the pot of the potted plant at them.