New aliens called Morthren arrive, kill off the old aliens. We are introduced to John Kincaid, and we lose Ironhorse and Norton in exchange. Thus, the show loses most of its fanbase and is cancelled because of the bad storylines. Oh yes, and Debi saves the world. There you go. I think I explained the second season in a nutshell.
But, for reviews of the good stuff- the first season- look no further.
Episode List
The Resurrection
The Walls of Jericho
Thy Kingdom Come
A Multitude of Idols
Eye For An Eye
The Second Seal
Goliath Is My Name
To Heal The Leper
The Good Samaritan
Epiphany
Among The Philistines
Choirs of Angels
Dust to Dust
He Feedeth Among the Lilies
The Prodigal Son
The Meek Shall Inherit
Unto Us a Child Is Born
The Last Supper
Vengeance is Mine
My Soul to Keep
So Shall Ye Reap
The Raising of Lazarus
The Angel of Death