HoS Quest Without a Trace

I've noticed on a few youtube videos people have been confused and wondering how you get into the house the old couple are in front of.

[Spoiler](/s "Head round the back of the house from the left of the couple you will pick up a scent you can follow. You end up choosing to either kill or spare them, they drop their key if you kill them.")

I did this before handing it in.