Possessive love: that's the theme Spark toys with in this marvelously economical, outrageously contrived, but gently shaded comedy-farce. The lovers in question all show up, one way or another, in Venice at the quiet Pensione Sofia, a shabby but sunny place run by two middle-aged sisters. First to arrive is pouty art-history student Robert, half-miserable from the recent break-up of his relationship in Paris with an older man, a rich and unflappable American named Curran. Then who should show up at the Pensione but Robert's father Arnold, a retired headmaster on an adulterous spree with a flashy gourmet cook. (Back home in England, Robert's disgruntled mother is hiring a slippery private investigator to get the goods on her straying hubby.) And then not only does Robert's friend Curran appear, but so does Robert's other love--artist Lina Pancev, a brusque Bulgarian defector who has come to Venice to search for the grave of her father, who was supposedly assassinated during World War II in the garden of. . . where else but the Pensione Sofia! Though Lina keeps protesting, ""I'm not in rivalry never with no one,"" all these lovers are indeed rivals--in a mild, polite way--and more players are added when the forces sent by Robert's mother arrive: a countess/private-eye who was long ago the lover of Lina's dead father; and an odd couple from Robert's home town who are determined to wrench Robert's father away from his gourmet-cook hussy. Spark whisks these characters to and fro across the canals just long enough, then shifts the focus to the secret of Lina's father's murder: Robert has discovered the truth and is blackmailing everyone in sight. And, appropriately, this revelation from the past uncovers yet another tussle between jealous, possessive rivals--those two nice sisters who run the Pensione. Occasionally hilarious, sometimes poignant (with Robert's mum back in England), but more often merely the ultimate in offbeat charm--a polished yet subdued Spark-ler from a one-of-a-kind talent.