This is a lot of five Double Fastback Spy books, published by Simon & Schuster in 1986.  The Fastback series were a set of small perfect-bound short story paperbacks which were used to test reading comprehension skills for high school students; the Fastbacks averaged 30 pages, Double Fastbacks 60.  Because they were distributed exclusively to schools and typically discarded after a few uses, they are all uncommon to rare.

The question sheet and answer key teaching aids, also rarely kept, are included.

Titles are:

The Last Red Rose by S.D. Jones
Claw the Cold, Cold Earth by A.G. Gersdorf
The Puppeteer by S.D. Jones
Against the Wall by Joanne Suter
The Black Gold Conspiracy by Stan Timmons

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Shipping combined for multiple purchases.  Delivery confirmation included on all domestic packages.