In an old lighthouse, where a twenty-four-candle lantern lights a sparkling blue-green sea, dwell a solitary keeper and his little companion -- a cat called Mackerel. Together the two climb up, up, up to watch over the nighttime sea and down, down, down to eat and play.

On one stormy night, the quick rush of a fierce wind darkens every candle. Soon an errant fishing boat, lost in the raging black sea, signals distress. Sure enough, it is the sudden glow of twenty-four flashing yellow lights that guide the boat away from danger. Just what could those new lights be?