Neelix introduces Chakotay to leola root. Chaks is not impressed. Meanwhile, Voyager detects another ship in orbit - a Kazon ship. The away team prepares to beam up, but Seska is missing. Chakotay finds her hiding from Kazon in a cave.
Later, Chaks and Seska have dinner together. Chakotay is upset that she nicked food reserves, especially when Neelix rings up to complain. Oh, BTW, Chaks and Seska have been shagging all this time, despite the scripts so far not even hinting at it.
Shortly afterwards, they receive a distress call from the Kazon ship they encountered earlier, and set off to help. Tuvok beams over with an away team, and they find dead Kazon and a sealed off area. One injured survivor, who gets taken back to Voyager to medical attention.
Tuvok reports that the explosion appears to have originated from Federation technology. He suggests that someone on Voyager may have provided the technology and Janeway tells him to investigate.
Team Torres works on a way to get through the force field to the device which exploded. Seska is upset that Chakotay won't let her help, and visits sick bay to check on the injured Kazon. While there, Kes and HoloDoc ask why she's never given a blood sample, and she says she had a childhood disease that prevents her from donating blood.
Seska beams over to the Kazon ship and makes an unsuccessful attempt to retrieve the device, and promptly ends up in sick bay.
Janeway, Tuvok and Chakotay interrogate Carey to see if he's the one giving tech to the Kazon, because a signal was sent from his station.
Another Kazon ship turns up, and the captain beams over to talk to the patient, who HoloDoc says has been saved through blood transfusions from the crew. Kazon Captain is not happy that Janeway won't let them take the ship, and Janeway is even more unhappy when one of the Kazon kills the patient. After the Kazon sod off, HoloDoc and Kes announce Seska isn't a Bajoran and is probably really a Cardassian. Dun dun, as they say, duuuuun!
Chakotay is flabbergasted and requests to be the one who questions her. An away team prepares to remove the device from the Kazon ship, and the Kazon captain complains, which leads to a dick measuring competition (Janeway won). The device, retrieved to engineering, turns out to be a Voyager food replicator.
Chakotay vists Seska in sick bay, and she claims that her blood doesn't show as Bajoran because of her childhood illness. Chaks and Tuvok set up a trap and then go play cards in engineering until Seska implicates herself.
They confront her, and she says that they need to make deals with the Kazon to get help in getting home. She promptly beams off to a Kazon ship (hooray for Federation security!) and Chakotay asks Tuvok how the hell all these people infiltrated his Maquis cell.