From the back of the book:
The Galactic Civil War loudly rages on countless worlds. However, few know of the quieter war between Rebel and Imperial intelligence agencies. It is a war of duplicity and stealth, of stolen plans and false identities. The spies who fight this war will never get the glory, but without them the Alliance cannot win.
Join the hidden war of deception and espionage in Cyphers and Masks. This sourcebook expands upon the Age of Rebellion Roleplaying Game, presenting new options for Spy characters as well as any other characters interested in covert operations. Disguise weapons, slice computers, infiltrate enemy bases, and more in Cyphers and Masks!
This supplemental rulebook includes:
• Expanded Player Character options including new Motivations, Duties, species and specialisations.
• New signature abilities that allow Spies to conduct counterespionage efforts and become mastrs of tradecraft.
• New weapons, armor, gear, and vehicles designed for black ops missions.
• GM guidance for running Spy-themed campaigns and crafting Spy rewards, plus new rules for concealing weapons and vehicles from enemy detection.