They do it with mirrors
Agatha Christie
Miss Marple (6)
Magician's Gambit
David Eddings
The Belgariad (3)
The Sealed Letter
Emma Donoghue
Lazarus Rising
David Sherman & Dan Cragg
Starfist (9)
Sword and citadel
Gene Wolfe
The Book of the New Sun (2)
Shadow and claw
The Book of the New Sun (1)