Realm of the Tri-Planets - Perry Rhodan Book 31
Description from the back of the book
When Perry Rhodan discovers the home world of Khrest and Thora he finds that three planets are literally, better than one. For Perry has to contfront not just Arkan I but Arkon II and Arkon III. And each planet is dedicated to a purpose all its own: one of them...war!
The warrior planet supplies a super battleship of space a mile long...and Perry Rhodan and his mutant crew find themselves serving under Thora on a deadly mission.
Deadly...and violent, when the Peacelord and his allies are faced with hundreds of berserk little-robots bent on destruction, in one of Perry Rhodan's greatest adventures.
Condition - Good, signs of wear on the cover and creases on the spine.