Edmond Hamilton 
Planets in Peril [EPUB ebook] 

They were the first arrivals from the other side of the cosmos.With the help of the Martian scientist Thrin, they had crossed the whirling black abyss of the fourth dimension — a dimension that had never been reached before!Now a man with skin of pure marble-white and a woman of unearthly beauty stood before the disbelieving eyes of Captain Future and the Futuremen. The strange couple stared back in awe and amazement — particularly at Captain Future."Here is the one, " the man said finally in his alien tongue. "He is the only one who can save us!"