Ace Double #D-345 first printing 1959 paperback. Condition is Fine (-): tight and very square with flat spine; faint line on spine; faint 1/2" fold-trace on "Voodoo" side; slight wear on "Plague" side. Age-tanning comes in 2 grades since the publisher used 2 qualities of paper: the first 60-odd pages on each side have almost no tanning at all (higher quality paper), and the rest shows the typical mild to moderate and uniform age-tanning that you expect in a fifty-year-old paperback. [While not frequent - this is a fairly common occurance in Double-books.] No stamps, marks or writing - a clean copy that looks unread.

An Ace Double from 1959, with both sides by Andre Norton (and both part of her "Solar Queen" series): Plague Ship, bound with Voodoo Planet - both under the pen-name of "Andrew North." The first book appeared in hardcover from Gnome Press in 1956; Voodoo Planet (a short novel) is original to this volume.

Plague Ship: cover by Ed Valigursky, 158 pages. Since I think the first-page blurb to be a little vague about the plot/set-up, I'm quoting from a review by my favorite reviewer:

...This, for my money, is the pure romance of strange places that Sam Moskowitz and others - including myself - have been lamenting as lost from present day SF. We open with Free Traders feeling their way into ticklish negotiations with a strange race, on a strange world, that you're made to feel is strange in every detail. Young Thorsen blunders into one success, which is almost offset by complete failure - then at the very moment when they seem to have their fortunes made, a mysterious illness strikes down member after member of the crew of the trader Solar Queen, until only the four junior members of the crew are left to bring her back to Earth. Mystery compound on mystery: why does that grand character, Sinbad the ship's cat, refuse to go near the hydroponics room? What is the meaning of the 'strange behavior of a hoobat?" What is the secret of the Big Burn? Recommended for teen-agers and for anyone else who doesn't demand social significance in his SF, and likes to be taken back those easy days when worlds were still strange to us all. [-P. Schuyler Miller, in Astounding October, 1956.]

(Bound with) Voodoo Planet: cover by Ed Emshwiller, 129 pages. 3rd in the "Solar Queen" series. Dane Thorsen finds himself embroiled in a battle of minds between the rational science of the spaceways and the hypnotic witchcraft of the mental wizard who ruled Xecho.
[more details - from a review by Miller, again]:
...The real hero is the ship's medic, Tau, who has made a study of magic on the many worlds where the Solar Queen has traded, and who is called upon to fight magic with magic on Khatka, a world colonized by African refugees. [-P. Schuyler Miller, in Astounding October, 1959.]