Mile-long spaceships, evil robots, galactic warlords with
maniacal laughs, and slimy green aliens with four brains
and six armpits. Don't be alarmed but we're not alone...
by Nicholas Fisk (1973)
First book in the Grinny series
A wrinkle in time
by Madeleine L'Engle (1962)
First book in the Time quintet series