Calling on the same engagingly dry wit and unique, brisk, present-tense style she used so successfully in Ruthann and Her Pig (1989), Porte creates two more unusual families. Bertha Segal's Dad, who sold ``military hardware,'' has vanished in the Bermuda triangle during a business trip, which leaves Bertha to cope with her little brothers (they're triplets) while her mother holds down two jobs. Her best friend Fanny's parents are rarely home; they're talent scouts who cooperate amiably in business but are secretly divorced. Fanny decides to take tap lessons, hoping to teach the triplets to dance so that they can become adorable stars and solve the Segal's financial problems; but it's Fanny who has turns out to have talent—while, incidentally, the exercise improves her health. Fanny's mom finally reveals the divorce, which is a relief to everyone, especially Fanny; Mr. Segal turns up—he's had amnesia, and is ready for a new job: selling sponges. The offbeat plot here is delightful (though fans may be startled to have a second book featuring the return of a long- lost parent); but it's the deceptively offhand, beautifully honed style, adroitly concealing Porte's unusually perceptive reading of children's needs and concerns, that makes this truly special. A funny book, especially appropriate for sharing aloud. Illustrations not seen.~(Fiction. 8-11)