A charming stranger arrives in sleepy Sleeford Lock. Only intrepid school reporter, Veena Vale, is suspicious of his arrival at a time when the riverside community is in trouble. But no one will listen to her except for Nightshade, the talking black cat. Together they consult wise woman Hetty Dimple on her barge, The Floating Witch. To solve the mystery, they must unravel an ancient curse, tell uncomfortable lies and bake an awful lot of flapjacks...