The Star Virus/ Mask of Chaos (Ace Double, 78400)

One goal of this series of Ace Double Reviews was to review at least one Ace Double by each of the most prolific contributors to the series. I believe with this book I have reviewed at least one by every author who wrote double digits of Ace Double halves. E. C. Tubb wrote 12, but I had already reviewed him. "David Grinnell" is a special case. This is actually a pseudonym for Don Wollheim, the editor for the vast majority of Ace Doubles. Wollheim wrote a total of 10 Ace Double halves, the last 6 under the "Grinnell" name (and one of those in collaboration with Lin Carter).