The Tok'ra have turned down SG-1's request for an alliance against the Goa'uld because as Garshaw explains the earthlings don't offer enough rewards to justify a security breech. And the fact that none of the humans will act as host for Selmak a Tok'ra whose host is dying does little to build trust. However Samantha Carter has an idea. Her father Gen. Jacob Carter is dying of cancer. If he will become a host it will save both his life and that of Selmak. But when she and O'Neill return to the Stargate to propose the idea to her father the Goa'uld tipped off by a spy launch an attack on the Tok'ra. The Tok'ra have enough warning to relocate but by the time O'Neill Carther and her father return the attack is underway. The bonding of two beings as sick as Gen. Carter and Selmak would be difficult under the best of circumstances. With Goa'uld death gliders filling the sky it requires even greater risk and urgency.