Reidel had been caring for the animals on the colony ship before its destruction. He hadn't expected to find himself the leader of the survivors. While there were only seven of them, but they were a varied group, both in psi powers and in temperment. He also had to deal with the people on the Closed Planet they had been marooned on... and then there were the enemy aliens to worry about.
Used availability for Marion Zimmer Bradley's Seven from the Stars
November 1979 : USA Mass Market Paperback
January 2010 : USA, Canada, UK Kindle edition