Te'rak, a Jaffa who wore the tattoo of Sokar, had been involved in Arkad's plot to attack Earth using cloaked cargo ships loaded with naquadah. A small contingent of Jaffa had already arrived on Earth with one of the cargo ships, however some of the Jaffa had begun to have second thoughts about the planned attack. Jacek, Vala's father, had known some of the Jaffa from a weapon smuggling operation he used to run, and he made contact with Te'rak outside Colorado Springs to negotiate a deal to sell the naquadah and split the profits. However, Daniel and Vala traced Jacek to the meeting with his contact, and when Te'rak fired his zat gun, Daniel responded by firing his handgun. Te'rak was killed, and because of his disappearance, De'vir and the other Jaffa involved in the mission changed their plans and intended to carry out the attack after all.
Episode Reference: Family Ties