Timmy Green's Blue Lake

By using a little imagination, Timmy Green creates a playland out of a blue plastic tarp in this rather dull picture book. The boy first lays out the sheet as the ``terribly treacherous'' Blue Lake, over which he captains a ship. The following morning Timmy's pal Sherry Lou ice-skates on the lake and slices it into strips, which Timmy transforms into a road and ultimately a high-flying kite. Bergman ( City Fox ) begins with an exciting and unpredictable premise, but never develops a cohesive story. Her somewhat stiff text reads like a series of disjointed vignettes, while the forced exchanges between Timmy and Sherry Lou consist of un-childlike dialogue. Ohlsson's illustrations glow with sunlight and often capture a spirit of adventure, but in a couple of spreads, his human figures resemble colorful blobs of paint. The inventive spirit of children's games has been more fancifully captured in numerous other picture books. Disappointingly, readers will quickly recognize that these youngsters have a less than captivating sense of fun. Ages 4-up. (Sept.)