The first season, which takes place a few weeks after the end of the mini-series, has the crew exhausted. The Cylons are in pursuit and the fleet has been forced to make 237 consecutive jumps, one every 33 minutes. But on the last jump they had to leave a ship behind, the Olympic Carrier. By coincidence, a passenger aboard this ship has evidence that Baltar was humanity's traitor to the Cylons. When the ship returns, without any communication and armed with nukes, Apollo is forced to blow it up before it reaches the fleet. In the second episode, most of the water supplies are sabotaged, forcing them to search planets for H2O deposits. There's a prison ship of over 1500 prisoners and they are offered points for their freedom if they help mine the ice for water. Yet their leader, Zarek (Richard Hatch)--a terrorist--doesn't want them to help and stages a revolt, holding members of the Galactica hostage. In the fourth episode 13 Viper pilots are killed when a drone accidently explodes, forcing them to begin training new pilots. Adama approaches Starbuck to do this but she's reluctant, still feeling responsible for the death of Zack, Adama's youngest son. He had failed his flight test yet she passed him because she was in love with--and engaged to--him. In "You Can't Go Home Again", Starbuck is shot down on a barren moon and only has two days of oxygen. Adama and Apollo begin a full-scale search but it's hopeless. Meanwhile, Starbuck comes across a damaged Cylon ship. She crawls inside and realizes it's a living organism. She removes its brain and figures out how to fly it back to the Galactica, where the Tyrell and the crew study it. Boomer, who doesn't know she's a Cylon, is drawn to the ship like it's a pet. Meanwhile, President Roslin, who is dying of Cancer, is taking Kamala Extract in hope of a cure. But it has side effects. In "Flesh and Bone" she has dreams of a Cylon agent which come true. This agent is captured and interrogated by Starbuck. He tells her that "all this has happened before" and also that they'll find Kobol, the original human colony. Before this human looking Cylon is jettisoned out the airlock he whispers to Roslin that Commander Adama is really a Cylon. She half believes him. In the next episode she's anxious for him to get tested by Baltar's new "Cylon test". While Baltar has indeed developed a way to tell the blood apart from human and Cylon he keeps the info to himself, such as when Sharon is tested. And when Commander Tigh's wife, Helen, mysteriously shows up to cause emotional havoc with her estranged husband, he keeps her results to himself as well. Can she be a Cylon? The season ends with President Roslin convincing Starbuck to fly the captured Cylon Raider back to Caprica to recover the Arrow of Apollo, which will give them a clue how to find Earth. You see, they have come across the planet Kobol and Roslin has another vision and thinks she's fated to lead her people to the lost 13th Colony. Meanwhile, Sharon encounters some Cylon duplicates of herself when she sets a nuclear bomb on a Cylon base ship and soon after shoots Adama in the chest. She's taken into custody while he lies bleeding on the bridge of the Galactica.
It's very interesting re-watching this first season after having watched the entire series. It's amazing how everything here plays out in the final episodes. Those writers stuck to their guns.