An asari war strategist needs fragments of Reaper code to predict enemy movements. Find a Reaper code fragment and deliver it to her at the Citadel embassy.
Alternative journal entry:
A Reaper code fragment was recovered from the geth consensus. Find someone on the Citadel who can use it.
Acquisition
After the Cerberus attack on the Citadel there's an Asari War Strategist on comms at the Embassy Offices part of the Citadel Embassies (near the elevator). She struggles to comprehend the Reapers' movements and even requests for code samples from Sovereign in the hope of finding counter-strategies. Simply eavesdropping on her will activate the mission in the journal.
Alternatively, you can straightaway acquire the code fragments from the geth consensus prior to resolving the main issues at Rannoch.
Walkthrough
The code fragment is found near the first infected data cluster you encounter, the segment that's glowing orange but cannot be destroyed by the Geth Combat Software. The code can also be bought from the Spectre Requisitions terminal if you didn't get it during the mission.
After collecting the code, go to the Asari War Strategist and give it to her. This gives you 5 Reputation, 30 experience and 1,000 credits. It also updates the Asari Second Fleet War Asset.
If you purchased the code fragment from the Spectre Requisitions terminal, you might not be able to give it to the War Strategist until you've left the Embassies level and come back.
If you overhear the war strategist again, she recommends redirecting forces to new coordinates based on the intel.
Trivia
- As Shepard starts in Armando-Owen Bailey's office after Priority: The Citadel II, it is almost impossible to not overhear the Asari War Strategist and obtain this mission on the Citadel. The War Strategist starts talking once Shepard is in proximity, which has a wide radius and even covers up to the elcor diplomat's location. By saving as far from the War Strategist as possible when she starts talking, before you get the mission notification, then reloading that save, her trigger is temporarily bypassed and allows for the acquisition of the mission during the trip to the geth consensus.