Duke Grey and his people were still looking for the trespasser and some pieces of evidence against Agatha. However, both had been very slippery. It was hard to locate the unassuming assailant since the person left no trace and could not even be tracked using magic or hounds. As a result, the duke's frown kept getting deeper each day since he really wanted to tear the perpetrator to pieces to get back his lost face.
And the pieces of evidence? The previous coven meeting could have been a good opportunity. Marian even wanted to join in the fun. But a few inexplicable things occurred to the two leads apart from the freezing incident, so the opportunity naturally slipped away.