Sign of the Unicorn1975
by Roger Zelazny
Eric is dead, and Corwin now rules Amber as Regent — but someone has murdered Caine and framed Corwin. Random tells his part of the story. Corwin decides to find out what happened to Brand who is either missing or dead, and begins to find his obsession with the throne is a two-edged sword that may cost him his life, as it has his brothers'.
— from OpenLibrary
19 editions at OpenLibrary