in a pile of snow and meeting up with her best friends, Maud Spellbody and Enid Nightshade, Ethel Hallow appears and tells Mildred that Miss Cackle wants to see her. Miss Cackle suggests to Mildred that she replaces Tabby. Last term, a third-year witch, Fenella Feverfew, transferred to Miss Pentangle's Academy several mountaintops away and left behind her sleek black cat, Ebony, since they have owls at Miss Pentangle's instead of black cats. Down in the kitchens, Mildred reluctantly hands over Tabby to Miss Tapioca (to catch mice), who gives her Ebony in return. Mildred is too upset to tell either Maud or Enid about it until after assembly. Miss Hardbroom announces that Mr Rowan-Webb, the frog-magician whom Mildred saved from the lily pond the previous term, has invited all the second-years to spend a week's holiday at his castle, Gloom Castle at Grim Cove. On the morning of departure, unable to bear the thought of a week without Tabby, Mildred sneaks down into the school kitchens, lets Ebony out of his cage and instead hides Tabby inside. When they reach Gloom Castle, they find that it is falling apart: the armchairs have springs and stuffing sticking out and there are no proper beds (apart from one, which Ethel Hallow immediately claims) other than old sleeping-bags, piles of pillows, and what appear to be hospital trolleys. Mildred gets an old sleeping-bag under the window, and realises she must divert attention away from Tabby. Mildred spots a boat attached to a breakwater and decides to hide Tabby in the cabin of the boat. After a wonderful day on the beach, Mildred tries to sneak some kippers to Tabby, but Ethel catches Mildred, who pretends to be looking for some mythical treasure on Cat's Head Rock in front of the cove in the boat on the breakwater. As the two head back up the cliff stairs, they witness Miss Hardbroom flying down to the beach on her broomstick with her own black cat, Morgana. Morgana runs to the boat and feeds on the kippers that were meant for Tabby. Miss Hardbroom spots both Tabby in the cabin and Morgana eating the fish. Stepping on board to investigate, she slips on a kipper, hits her head and falls unconscious. Sneaking out to feed Tabby again, Mildred is confronted by Ethel, who snidely tells her that she has untied the boat and let it