You grab your bow and sling the quiver over your shoulder. You are a bit rusty but it is safer to snipe from a distance, instead of charging in.

You race down the stairs to see if an intruder is in the house. You are sure you locked the front door behind you when you arived so there are only 2 possibilities. Something came from the back door, or something was already inside, the only room that could have that loud of a bang would be the Discovery room, which has you Grandfather's artifacts from his travels.

The room could be locked from the inside, but there should be a spare key in the kitchen.

You Can:

Go to the Kitchen for the key

Check if the door is unlocked

(Be creative I'll use whatever comment is interesting.)