Android at Arms

Science-fiction adventure by Andre Norton. Andas Kastor regains self-awareness on a barren prison planet where he has been incarcerated by unknown entities for unknown reasons. A power failure frees him and several companions. When they compare notes, they discover that they were all involved in critical time-sensitive situations - in different years. They also discover that the prison planet includes highly advanced technology which appears to be for creating android duplicates of beings of various races, and speculate that they may have been kidnapped in order to be duplicated and replaced.

The ill-assorted comrades find a ship with navigation tapes for various planets, including Andas' home world of Inyanga. After a series of planet-hopping adventures, including some double-crosses and a few losses, Andas and his companions make it, only to find that the current ruler is...Andas Kastor, decades older and with three daughters. And then things really start to get wild....

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Tropes associated with Android at Arms:

 * After the End:
 * Ambiguous Clone Ending
 * Apparently Humanoid Merfolk: Elys appears to be this, but turns out in the end to be Fish People.
 * Artifact of Doom
 * Author Appeal: Yolyos, a Salariki cat-alien.
 * Badass Native (Andas)
 * Bathing Beauty (Elys, but with clothes on, the spoilsport)
 * Becoming the Mask
 * Blood Brothers (Yolyos suggests this to Andas, who accepts)
 * Casual Interstellar Travel
 * Cool Gate
 * Cool Key
 * Darkest Hour: several in relatively quick succession.
 * Due to The Dead
 * Eldritch Abominations: (the night crawlers)
 * Fat Bastard:
 * Feudal Future (Inyanga)
 * Fire-Forged Friends: Andas and Yolyos, not even of the same species, become fast friends and finally Blood Brothers as a direct result of their harrowing adventures.
 * I Gave My Word
 * Lost Superweapon
 * No One Could Survive That
 * No One Gets Left Behind
 * Omnicidal Maniac:
 * Ridiculously Humanoid/Alien Androids
 * Rip Van Winkle
 * Stranger in A Familiar Land
 * The Mole
 * Thieves Guild (In space!)
 * Tomatoes In The Mirror
 * Vain Sorceress: Kidaya, when she finally shows up
 * A World Half Full:
 * You Can't Go Home Again