British author Mark, best known to-date for her children's fiction, makes an impressive debut with this quietly overpowering novel of madness and regret. Mark's well-crafted work operates on the assumption that seemingly minor incidents and coincidences have the potential to trigger events of major consequence. John McEvoy, a schoolteacher and father of two, receives a copy of an ""inspirational"" book from a girlfriend he can barely remember. It's a memoir of a one-time mental patient whom McEvory doesn't immediately recognize, but who on reflection turns out to be a remote acquaintance from the early 60's. Why has McEvoy been sent this book? Poring over the defensive outburst, appropriately titled Acid Test, he realizes that he shows up in the work, under a different name, as a calculating, charming destroyer of hearts central to Acid Test's vitriol. The fact that he hardly remembers the author, or the onetime girlfriend who sent it to him as a gesture of revenge (""I do hope you'll read it""), antagonizes him into dealing with the needling question of how much he is still the ""Michael"" schemer of Acid Test, or whether in fact he ever was such a character. The question lingers because Acid Test portrays him as being responsible for the suicide of another early 60's acquaintance whom McEvoy, again, barely remembers, Meanwhile. McEvoy's author-friend Geneva, spouting large chunks of narrative theory, can't assuage his guilt; and since Acid Test was sent by an ex-girlfriend, McEvoy can't share the quandary with his jealous wife Sarah. An insignificant encounter with Geneva's poet-friend Ruth leads to a full-fledged affair between McEvoy and the poet; and as wile Sarah's jealousy builds to a maniacal pitch, it's clear that McEvoy/Michael is indeed capable of driving someone to suicide--though the victim this time around is the one we suspect least. Masterfully paced, subtle work.