Borgen (1902-1979) is considered one of Norway's major writers; and this 1955 novel, first of a trilogy, is indeed impressive in its first third, if far less so after that. Wilfred Sagen, at 14, is a long-locked and pampered ""Lillelord,"" the ""house's little lord"" to his widowed mother (the setting is pre-WW I Oslo). An exquisite and precocious pianist, Wilfred can more than hold his own as soloist in a Mozart concerto--or as the brightest boy in class at school. But high esteem and favored-child adoration do not block out a deeply perverse side to him, one that secretly involves forgery, manipulation, even hooligan-leading sprees of violence: ""He himself had to create this something that he had to protect himself against, and he felt very happy with this whatever it was that freed him from the fact that everyone knew everything."" For a time, Wilfred's instability is channeled into sexual awakenings: his seduction of an unhappy young aunt; the discovery that his dead father had a son by a mistress. But when he finds his father's ex-lover dead in the desolate cottage she lived in alone, Wilfred promptly cracks--and is traumatically rendered mute. (He finds that he likes the situation, the odd power he now wields over those who speak.) Finally, then, his uncle takes him to a much-talked-about doctor in Vienna (clearly Freud), who proceeds to cure him; and Wilfred is once again on the way to regaining his other half--though the book ends inconclusively, seemingly banked in order to provide heat for the rest of the trilogy. Wilfred's intelligence, wholly at the service of cynicism, self-regard, and emotional manipulation, is the finely-imagined, involving idea here. Yet, after the book is only a third done, Borgen starts belaboring the split-personality business and loses the kernel. An intriguing, if uneven, serving of Scandinavian fiction, then--and perhaps the succeeding volumes of the trilogy (not scheduled for US publication at this time) will more consistently demonstrate Borgen's distinctive talents.