The scene is an Inn somewhere in the Empire (or wherever). The adventures finds a body close to the inn. The murder has taken place during the night which means that all the guest are considered suspects.
When the party found the body they discovered the following:
Closer study of the footprints reveals a distinct mark on the killers left sole. A capitol M - maybe an initial for the murderers name?
The party discovered that the suspect had some very compromising boots in his locker.
HOWEVER: Closer study of the boots reveals that the M is not mirrored in the snow, indicating that the most obvious suspect is being framed. Who the real killer is up to the GM.