The trailer for Greta Gerwig’s long-awaited adaptation of C.S. Lewis’s “The Magician’s Nephew” has finally arrived, and it was, as expected, catastrophic.

Kaleidoscopic glimpses of alien worlds are sandwiched between dreary, dystopian shots of England, while Lewis’s beloved characters seem to have undergone their own disenchanting transformations. Jadis, the future White Witch, bears a striking ...