Ace Double D-205 from 1957, the classic flip format with two complete novels in one. 

One side is The Earth in Peril, a short story anthology edited by Donald A. Wollheim featuring Murray Leinster, A.E. Van Vogt, C.M. Kornbluth, Edmond Hamilton, Bryce Walton, and H.G. Wells. Flip it over and you get Who Speaks of Conquest? by British SF writer Lan Wright, a full alien invasion novel. Cover art is by Ed Emshwiller and Stanley Meltzoff, two of the most iconic names in golden age sci-fi illustration. Emshwiller's pulp covers are actively collected on their own. 

This is the first and only printing in this format. Ace Doubles from the D-series are consistently sought out by vintage paperback collectors, and this one hits a lot of the right notes — alien invasion theme, an editorial heavyweight in Wollheim, and a stacked contributor list on the anthology side.

Please look at photos closely for condition. Packed and shipped with care from a smoke-free home. Check out my shop for hundreds of high-quality vintage objects, quality clothing, hand made items, and antique books. Combined discounted shipping always available. Questions welcome... I love meeting my customers! Alexandra, AKA Delicious Alex 📚 📦 💌