Synthetic Men of Mars

Synthetic Men of Mars is the ninth Barsoom novel by Edgar Rice Burroughs, first published in 1939.

When the warrior Vor Daj is captured and his mind is transplanted into the body of a hormad — a monstrous artificial being created by the mad scientist Ras Thavas — he must fight his way back to his true form while his commander John Carter and the queen Dejah Thoris are held captive in the same hidden city.

As Thavas's creations overrun the city of Morbus, the battle for Barsoom's future is decided by the daring of those caught between science, madness, and the savage laws of Mars.