Steal Across the Sky | 
pick10,000 years ago aliens committed a great wrong against the human race. Now they have returned to Earth to atone by taking select Earthlings to act as Witnesses on other planets.
The first part in which we follow the work of one team of Witnesses was by far the best. The second and third parts lagged a bit and were not as exciting as they could or should have been.
The first part puts into high pick territory but the other parts drag it down to a low pick. 3d