“So. Why’re you doing tap?” “The sex appeal.” Movement Therapy is the debut stage play from Cold Plunge Productions. Written by Margot Pue, it is a new 60-minute comedy that explores how movement, specifically tap dance, can help people process grief and find community. Fiona finds herself freshly and unexpectedly single, living in a flat she can’t afford without her ex, Jack, who got full custody of their shared friend group. All she has to do is move on, which is proving challenging since no one in her family wants to uninvite Jack from her brother’s wedding. Her only solace is her weekly…