Toronto cop Charlie Salter, likable as ever (Smoke Detector, etc.), is now vacationing with wife and kids on pretty, quiet Prince Edward Island--where the mystery turns out to be a lot less substantial than the island atmosphere. Local historian/teacher Clive Elton has been murdered, having apparently interrupted the elusive house-robber who's been plaguing the neighborhood in recent months. But could Elton's death actually be connected to his role in recovering the Island's ""Great Silver Seal,"" missing since the 1770's? Supposedly found by a collector in Massachusetts, the seal was about to be purchased for $20,000 by a group of local patriots--including Charlie's bigwig father-in-law--once it had been authenticated by Elton. So: has the seal been stolen? Or was Elton killed as part of a scheme involving an antiquity-dealer from Toronto (who's hanging around suspiciously)? Things start to become clear when the prime robbery suspect--flashy handyman/ tinker Jim Brady, an aging Casanova--also turns up dead. But the whole truth about the two murders and the seal scare won't emerge till after Charlie (working with the P.E.I. constabulary) nudges several folksy locals into sheepish confessions. Wright, always fond of small-scale plots, is downright skimpy this time, with two short-story notions lightly intertwined. Still, if the puzzle is wispily uninvolving, the low-key comedy--charming father/son interplay, foul-houseguest tribulations--is delightfully on-target; and the local color is gently irresistible, especially for those already familiar with P.E.I.'s unassuming splendors.