Pathfinder Adventure Path #173: Doorway to the Red Star (Strength of Thousands 5 of 6)

Soar above a planet of adventure! The trail of a long-vanished ally leads to the other side of a magical portal called the Doorway to the Red Star. The heroes must earn the trust of the portal's guardians then travel through it—to another planet of red sands and high adventure! Working to gain allies among scholarly brain-people and shifty ratfolk, the heroes must infiltrate a massive airship and fight to free their ally from an insidious trap on an alien world!