“But it’s Nathan Thomas, as this production’s Bert (the chimney sweep who captures Mary Poppins’ heart, if even for a moment, and the audience’s for the entirety of the play) who virtually steals the show with his expressive, thoroughly committed performance. Charming and affable, Thomas is remarkably self-assured with stage presence that rivals Hill’s, completely filling the theatre with his stunning performance, particularly as he leads the ensemble through Roman’s “Step in Time” choreography with elan and panache.”