Fish-story follow-up to the popular fantasy-comedy "Miranda" finds Glynis Johns reprising her role as the mischievous mermaid, who now makes the acquaintance of a stuffy schoolmarm (Johns, again), who's her exact double─except for the legs, of course. When the tutor has to step out of town, all it takes is a wheelchair for Miranda to assume her identity, and cause her romantic havoc. Donald Sinden, Anne Crawford, Margaret Rutherford co-star. 82 min. Standard; Soundtrack: English Dolby Digital stereo; Subtitles: English.