More like The Crystal Prison

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The Thief of AlwaysNovel
Clive Barkerstandalone novel1992
Eerie in tone, set in otherworld.
“Once inside, Harvey meets fellow children Wendell and Lulu, the elderly caretaker Mrs. Griffin and her cats, and settles into a routine of enchantment that starts to feel too perfect.”
from the catalogue
The ScholomanceSeries
series3 books2020
Tense in tone, about magic schools and wizards.
Start with A Deadly Education →
NarniaUniverse
universe38 books1950
Portal fantasy.
“Once there is a wardrobe at the back of a spare room, and behind the fur coats the wood gives way to snow, and a lamp-post burns alone among the trees.”
from the catalogue
Start with The Lion, the Witch and the Wardrobe →
includes Narnia, Narnia Solo Adventures
The AncestorSeries
series4 books2017
Epic fantasy, about magic schools.
“The three novels tell the story of Nona Grey, a peasant girl with mystical abilities.”
from the catalogue
Start with Red Sister →
Deptford MiceSeries
series3 books1989
Fantasy and dark fantasy, dark in tone, set in secondary world.
“Robin Jarvis completed the trilogy with The Crystal Prison and The Final Reckoning within a year of the first book.”
from the catalogue
Start with The Dark Portal →
The WitchesNovel
Roald Dahlstandalone novel1983
Tense in tone, about witches, set in contemporary.
“A dark fantasy, the story is set partly in Norway and partly in England, and features the experiences of a young English boy and his Norwegian grandmother in a world where child-hating societies of witches secretly exist in every country.”
from the catalogue