British author Billington (Loving Attitudes, 1988, etc.) sets out for a romp in this quicksilver collection of interconnecting novellas about a pair of lovers whose stars cross in five different time frames, but always in the same place. The Theo and Mathilda of the present are only sketchily rendered, like bookends, at the opening and finish here. They are a young married couple who purchase one of several dozen units constructed on the site of an ancient monastery in the West Country of England, and settle down, with Theo vowing that if they're ever parted, it will be ``only a temporary separation.'' His claim rings true, since the first Theo and Mathilda meet back in 770he a poetical young oaf, taken in by a ragtag collection of monks, she the daughter of King Cynewulf of Wessex, prideful, independent, but utterly drawn to Theo. Together, they build a church and connecting monastery and convent, with Theo as the unlikely abbot and Mathilda as the abbess. For years they struggle against their love, until Viking raiders finish them both off before any fleshly sin gets committed. Their next reincarnation comes during Henry IV's pillaging of England's monasteries, when Mathilda abducts the displaced monk Theo and has her way with him. Three hundred years later, Theo is an eccentric herpetologist and Mathilda his long-suffering wife; and when l980 rolls around, the two of them finally arrive at the fate they seem to have been aiming at all along: They're both mad, incarcerated in a mental hospital but embarking on a love affair nonetheless. Down through the ages, the Theo and Mathilda tales support Shakespeare's observation about the close connection between lunatics and lovers. Along the way, Billington reuses themes and details in entertaining ways, and studies a love relationship from a variety of anglesall of which makes for loony little valentine of a book, sappy but always intelligent.