Very tight and square - this looks new/unread with light shelf wear (faint in middle of front cover; light to noticeable rubbing to back cover.) Age tanning is very mild - less than expected for its age.

City Under the Sea - first book appearance was as half of an Ace Double in 1957; serialized in New Worlds (1957) as "Green Destiny." It's a pretty good book - one of Bulmer's best (several British printings, and 3 American printings.)

Commander Jeremy Dodge is kidnapped into slavery for the undersea farms. His kidnappers, surgically adapted for the depths, seem to be in conflict with nonhuman Aliens. The surface people want to drop a nuke...