Of the episodes I’ve seen so far of this miniseries (which is most of them), tonight’s installment is the most effective and artistically satisfying. It flashes back, extensively, to the time choreographer Bob Fosse (played by Sam Rockwell) met dancer and actress Gwen Verdon (played by Michelle Williams). Their meeting, with her auditioning for a role he’s choreographing, is played as a verbal and nonverbal duet: They circle one another, probe for weaknesses, lob jokes, and sniff each other out, eventually deciding they’re mutually very attracted to each other, and to their respective talents. Not all of Fosse/Verdon works, but these scenes do – and Williams, especially, is superb.