John W Campbell Jr - The Black Star Trilogy
The Black Star Passes – A sky pirate armed with superior weapons of his own invention. First contact with an alien race dangerous enough to threaten the safety of two planets. The arrival of an unseen dark sun whose attendant marauders aimed at the very end of civilization in this Solar System. These were the three challenges that tested the skill and minds of the brilliant team of scientist-astronauts Arcot, Wade, and Morey.
Islands of Space – As Earth's faster-than-light spaceship hung in the void between galaxies, Arcot, Wade, Morey and Fuller could see below them, like a vast shining horizon, the mass of stars that formed their own island universe. The ship filled with the strain of flowing energy, and sparks snapped in the air of the control room as they raced through the darkness of intergalactic space. But suddenly, far off to their left and far to their right, they saw two shining ships paralleling their course! They held grimly to the course of the Earth ship, bracketing it like an official guard. The Earth scientists stared at them in wonder. "Lord," muttered Morey, "where can they have come from?"
Invaders from the Infinite – The famous scientific trio of Arcot, Wade and Morey, challenged by the most ruthless aliens in all the universes, blasted off on an intergalactic search for defenses against the invaders of Earth and all her allies. World after world was visited, secret after secret unleashed, and turned to mighty weapons of intense force – and still the Thessian enemy seemed to grow in power and ferocity. Mighty battles between huge space armadas were but skirmishes in the galactic war, as the invincible aliens savagely advanced and the Earth team hurled bolt after bolt of pure ravening energy – until it appeared that the universe itself might end in one final flare of furious torrential power.