The Doctor. A survivor of the nearly extinguished "elemental" Time Lord race, a near-total amnesiac who stakes Earth's very existence on a ritualistic marriage in 1782 — all to save humanity from becoming less than apes. Sabbath. A former British intelligence agent, insatiably curious and deeming himself an infinitely preferable guardian of humanity. It's only a matter of time before he exploits the Doctor's naivete or eliminates him — possibly both.