An Innovative Murder for the Season: A Lt. Sinclair Plate Mystery in Sand Waves

A massive flood threatens as the Christmas season dawns in the Houston Galveston area. People living there don't expect a white Christmas but they hope for a dry Christmas.
It is hot, humid and floodwaters everywhere have trapped people in inconvenient and dangerous situations.
At a small specialty store in a high income community, a dozen or so people are trapped for 3 days and 2 nights. On the surface most appear to be strangers caught at random.
Then there is a murder and it turns out the only real stranger among them is a detective whose presence is hardly coincidental.