The Crossroads of Time, in Ace Double #D-164: Mankind on the Run by
Gordon R. Dickson / The Crossroads of Time by Andre Norton (Ace Books,
1956).
VARIANTS
Debut. The Crossroads of Time, in Ace Double #D-164: Mankind on the Run by Gordon R. Dickson / The Crossroads of Time by Andre Norton (Ace Books, 1956).