Booster Dragon's Maze.

The Guilds of Ravnica are under the spell of a huge puzzle that runs through the metropolis. There are rumors that the person who is the first to crack the puzzle will get earth-shattering power. All ten Guilds are in a race to be the first to solve the mystery. Does your Guild win the ultimate prize?

Dragon's Maze is the third set in the Return to Ravnica Block and consists of 156 cards.

A booster Dragon's Maze contains 15 Magic: the Gathering cards including 1 rare, 3 uncommons and 10 commons. In approximately 1 in eight boosters you will find no rare, but a mythic rare! At the place where you would normally find a basic land, you will find an extra common, rare or mythic rare land! These rare lands are the shocklands from Return to Ravnica and Gatecrash!

Note: the description is machine translated and might contain errors.