Darvo's transmission.
A Favor For Darvo was a limited alert that was available from 27 November until 29 November 2013 at 11:50am EST. It starts off with Darvo contacting many Tenno to ask for help.
Gameplay
A Favor For Darvo is hosted as a regular Corpus Mobile Defense with three terminals to hack. While hacking the third and final terminal, you will be ambushed by the Stalker which means you must fight him while at the same time protecting the terminal from oncoming Corpus troops.
Rewards for completing the mission was a Script error: The function "Forma" does not exist. blueprint and 
9,500.
Plot
Darvo's Apology to the Tenno after the alert.
Killing the Stalker
Still being hunted by The Stalker after discounting the What Stalker? pack, Darvo hatches a plan to lure the Stalker into thinking he is aboard one of his ships, using the assistance of the Tenno (who had no idea they are being used as bait) to hack terminals, in order to get the Stalker's attention.
As the alert progresses to the third terminal, lights will flicker, and then the Stalker will abruptly appear in the area, only to find out the Tenno instead of Darvo to be killed.
Let Me Make It Up To You
After the event, commotion was risen from Darvo's attempt to bait the Stalker. Darvo decided to apologize to the Tenno, making it up to them by setting up his Market discounts once more.
Trivia
- Unlike most Stalker encounters, getting killed by him during this alert does not result in him leaving afterward.