Ace (M-154) 1966 paperback (hardcover was 1961 from Fantasy Press.) Cover by Gray Morrow, 192 pages, 45 cent cover price. Condition is VG to VG+: tight with 1/16" tilt, spine has 1 line and some wear to the top 3/4", light overall wear as faint lines next to spine front and back, age tanning is mild and uniform / average for its vintage (insides of covers are darker.) No stamps, marks or writing - a clean copy.

John W. Campbell's Invaders from the Infinite (copyright 1961.) This is third in the series begun with The Black Star Passes - featuring the team of Arcot, Wade, and Morey. Revised from original magazine version in Amazing Stories Quarterly Spring/Summer 1932. Since I haven't read this - I'll have to quote excerpts from P. Schuyler Miller's review in Analog September 1961:

"This yarn was close to the peak of the "super physics" school of that era, which John and Dr. E. E. Smith carved out of a corner of the space-opera field. Skittering around the frontiers of physical and chemical theory, using something that was not quite scientific double-talk to explain the miracles that the heroes brought out of thin air almost by snapping their fingers, they nevertheless maintained a pace and created a spirit of excitement that typified the science fiction of their day. Their readers put down the magazine convinced that if scientists weren't such stupid clods, all these things could come to pass next Tuesday."

"In this, utterly ruthless, utterly villianous villians from the other side of nowhere set out to exterminate all competition in our galaxy. A race of super-dogs come to Earth for help, and our trio of supermen glady give it. They zip around the universe collecting allies and weapons, fighting skirmish after skirmish and battle after battle... travel in time as well as space... oppose irresistible forces with immovable screens... and, of course, win hands down. The fireworks are terrific, and there's never time to get choosy about the logic." [-P. Schuyler Miller]