Pretty average collection of Wyndham stories, mildly enjoyable but not up to his usual standards I think. There's only five stories in here - more novelette/novella length than typical shorts, with three of them concerned in some way with space exploration, whether of Mars or Venus. One of the others ("The Third Vibrator") is the worst of the lot and pretty dire really, but it's balanced out by the best, a creepy Venusian alien of terrible hunger in "Invisible Monster".

A collection for Wyndham completists more than anything else, I think.