|Out of universe information|
In 2002 Cross, together with Agent Singer, was undercover in Steveston, Oregon, when the NID found out that the whole town was taken over by cloned Goa'uld symbiotes. These symbiotes were building a spaceship so that they could join with their brethren in the galaxy but the NID hoped to get the ship once it was completed. Cross was undercover working as a policeman in the city. When SG-1 examined the city after getting a warning, Cross and Singer took Teal'c and Jonas Quinn with them and informed them about the situation. Shortly thereafter, Singer revealed himself as a Goa'uld, stunned Cross, Teal'c and Jonas and brought them to the others.
Cross was then blended with a Goa'uld as well and ordered to infect the remainder of the NID headquarters with symbiotes, together with Singer. Before he could leave the town, he was stopped by Major Samantha Carter who stunned the two agents with a Zat'nik'tel. Following this, the Goa'uld were successfully removed not only from the agents, but the townspeople as well. (SG1: "Nightwalkers")