Find Spender on the Nexus Edit
When Ryder first arrives back on the Nexus after obtaining Drack as a squad member, you may overhear a conversation between Spender and a salarian technician named Del Jasin. Spender berates the salarian for incompetence and making frivolous requests for parts to fix the air filtration system on the Nexus. After Spender leaves, Ryder can ask her if Spender is always such an abusive supervisor which she affirms. Del suggests that Ryder undermine Spender's reputation with the Nexus leadership in order to get him removed.
Talk to Kesh Edit
Find Kesh in her office, she'll reveal that Spender has gained the favor of the Nexus leadership but she believes he might be communicating with the exiles. She suggests speaking with Kandros to obtain the proof of his betrayal.
Speak with Kandros Edit
Speak to Kandros, let him know you're investigating a possible link between Spender and the Nexus uprising, he'll note that there were some discrepancies but that there hasn't been time to dig deeper to find answers. He'll give you access to the video archives.
Review Nexus security footage Edit
Unfortunately the security footage is corrupted and there isn't anything definitive about Spender's actions that prove he is guilty.
Confront Spender Edit
Speak to Spender, he denies any wrongdoing and warns Ryder off further investigating. At this point the mission is put on hold until Ryder can located the planet mentioned in the security footage (+530XP).