The trail to solve the mystery of Jimi Stonefree leads Echo and Mu to a glittering purple city ruled by Denka.

Echo and Mu continue their journey to find Jimi and end up in Londinium. In Londinium, Mu is asked to participate in their plans for Christmas, which is one week away.

With the appearance of Listeners, King of the Earless, the Earless have grown ever more destructive. Roz, Denka, Kevin, and Bilin must each decide how they want to face this crisis.